Banana Bread Tiramisu
I have provided instructions for making this tiramisu either in glass cups or jars (the easy way) or encased in chocolate shells (the more complicated way.) Whichever presentation method you choose, I do recommend spreading the assembly out over the course of several days. Some of the components, like the banana bread and dulce de leche, will take time to bake and cool, and the assembled tiramisus will need to be refrigerated for at least 4 hours to set before eating them. In general this dessert does keep well for several days, but if you intend to serve them several days after assembling them, consider omitting the caramelized banana component to keep the dessert fresher longer.
For the Banana Bread:
4 large eggs, at room temperature
14 oz (2 cups) granulated sugar
2½ oz (1/3 cup) packed brown sugar
24 oz (3 cups) mashed ripe bananas, from about 6 bananas
8 oz (1 cup) vegetable or liquid coconut oil
2 tsp vanilla extract
2 oz (1/4 cup) Greek yogurt or sour cream
13¾ oz (3¼ cups) all-purpose flour
2 tsp baking soda
2 tsp ground cinnamon
½ tsp salt
For the Dulce de Leche Soaking Syrup:
14 oz dulce de leche or sweetened condensed milk
¼ cup milk
For the Caramelized Bananas:
2 tbsp butter
¼ cup brown sugar
1 tbsp rum (can substitute water or orange juice)
1 tsp vanilla extract
¼ tsp cinnamon
4 large or 5 medium bananas
For the Mascarpone Cream:
6 egg yolks, at room temperature
7 oz (1 cup) granulated sugar
1 lb mascarpone cheese
¼ tsp salt
2 tsp vanilla extract
¾ cup heavy cream
1½ cups heavy cream
½ cup powdered sugar
Chocolate pearls or other chocolate decorations (optional)
For the Optional Chocolate Shell:
1 lb chocolate candy coating or tempered chocolate (see here for tempering instructions. I don't recommend using plain chocolate that has been melted but not tempered)
Acetate cake collar strips, 4" high
To Make the Banana Bread:
Preheat the oven to 350 F and spray two 9x5-inch loaf pans with nonstick cooking spray. Combine the eggs and both sugars in the bowl of a large stand mixer fitted with the paddle attachment. Beat them on medium speed until well-mixed, then turn the speed to low, add the mashed bananas and mix them in. Finally, mix in the oil, vanilla extract, and Greek yogurt.
In a separate bowl, whisk together the flour, baking soda, cinnamon, and salt. With the mixer running on low, add the dry ingredients and mix until just a few streaks of flour remain. Stop the mixer and finish mixing by hand, scraping the bottom and sides of the bowl well with a spatula until everything is well-incorporated.
Divide the batter evenly between the two loaf pans (if you want to weigh it out, there should be 36 oz in each pan.) Bake the loaves at 350 F for 50-60 minutes, until a toothpick inserted into the center comes out clean. If the tops are getting too dark during baking, cover them loosely with foil during the final baking stages.
Cool the loaves on a wire rack for 20 minutes, then turn them out of the pans and let them cool completely.
To Make the Dulce de Leche Soaking Syrup:
If you are using store-bought dulce de leche, pour it into a bowl and whisk in the milk, a spoonful at a time, until you have a thin consistency similar to heavy cream.
If you will be making the dulce de leche yourself, submerge a can of sweetened condensed milk in a pan of water and bring the water to a simmer. Simmer the can for 3 hours on the stovetop, adding more water if necessary so that the can is always covered. After 3 hours take the can out of the water, cool the can completely, then open it and proceed as above.
To Make the Caramelized Bananas:
Slice the bananas in half, then cut the halves into 2-3 pieces lengthwise. So as not to overcrowd the bananas while cooking, make them in two batches. Place a large saucepan over medium-high heat, and once hot, melt half of the butter in the pan. Add half of the sugar, rum, vanilla extract, and cinnamon, and stir until you have a bubbling syrup. Add half of the banana slices and cook them, undisturbed, for 30 seconds. Carefully turn the bananas over and cook for an additional 60 seconds. Remove the bananas from the pan and repeat the produced with the second batch of bananas (no need to clean the pan in between!).
To Make the Mascarpone Cream:
Place the egg yolks and sugar in the large bowl of a stand mixer fitted with a whisk attachment. Beat the yolks and sugar together on medium-high speed until they are very thick and pale, about 2-3 minutes. When you stop the mixer and lift up the whisk, the yolks should slowly drip from the whisk in a thick ribbon.
Add the mascarpone cheese, salt, and vanilla extract, and beat on medium-low until the cheese is incorporated and the mixture is free of lumps. Don’t overbeat, or beat too quickly, since mascarpone is prone to breaking if it’s overworked!
Transfer the mascarpone cheese to another bowl, and in the same mixing bowl—no need to clean it—place the remaining ¾ cup heavy cream. Whip the cream to firm peaks, then gently fold it into the cheese in several batches.
To Assemble in Glass Cups:
The easiest way to make these desserts is to assemble them in six 10-oz dishes or cups. Slice the banana bread into ½-inch slices, then use a round cutter to cut the slices into circles the width of the dishes you'll be using. If your dishes are wider than the slices, you can press two slices together to cut out the circles, or just use cubes of banana bread for a less precise look.
Hold a circle of banana bread in one hand, and gently spoon some of the dulce de leche soaking syrup over it. The banana bread will be too delicate to really dip in the dulce de leche, so you're just going for a quick soaking while you hold it. Place a layer of banana bread into the bottom of your cup, then repeat until all of the dishes have a first layer of banana bread.
Top each piece of banana bread with 1-2 pieces of caramelized bananas, trimming them if necessary so they fit. Spoon a thick layer of the mascarpone cream over the bananas—you may find that it’s easier to put the cream into a pastry bag with a round tip, or a plastic bag with the corner snipped off. Once all of the bananas have a layer of mascarpone, repeat the layers, adding more soaked banana bread, caramelized bananas, and mascarpone, until you have made 3 layers of each. Make sure that you end with a layer of mascarpone cheese.
Whip the cream and powdered sugar together until you have stiff peaks. Finish the tiramisus with a big dollop of whipped cream and a scattering of chocolate pearls, sprinkles, or shavings. Refrigerate for at least 2 hours, then serve!
To Assemble in Chocolate Shells:
If you want to assemble the tiramisus in edible chocolate shells, you will need 4" tall acetate cake collars. Wind the acetate into a 3" circle, tape it together, then place it on a cardboard round or small plate. Repeat until you have 6 acetate circles. This is what you will assemble your tiramisus in. Assemble the tiramisu as described above, but do not top them with whipped cream yet. After you have added the final layer of mascarpone to each one, refrigerate the tiramisus for at least 4 hours, so they will be firm.
Measure the circumference of the tiramisus and cut six additional acetate strips that will fit all the way around the tiramisus. Using scissors, slice through the acetate collars that were around the tiramisus and remove them.
Cover your work surface with parchment or waxed paper, and lay an acetate strip out on the paper. Melt the candy coating in a large microwave-safe bowl, or temper the chocolate. Spoon some of the melted chocolate onto the acetate in even intervals. Remember that it is going to be spread in a thin layer, so apply it sparingly. You can always add more later if you need to.
Using an offset spatula, spread the chocolate in a thin layer over the entire acetate strip, so that all of the edges are covered. It’s okay if the chocolate goes past the edges. Allow the chocolate to sit for about 5 minutes, until it just begins to set around the edges but is not fully hard or brittle.
Lift up the chocolate-covered strip of acetate and carefully place one edge against the side of the tiramisu, pressing the wet chocolate directly against the edge. Wrap it entirely around the tiramisu and press the ends together. Tape the outside of the acetate strip to secure it around the sides of the tiramisu. Place the dessert in the refrigerator to fully set the chocolate for at least 25 minutes. As you get more comfortable with the prodedure, you can do several at once instead of one at a time.
Once the chocolate is firm, peel back the tape and carefully unwind the strip of acetate, peeling it off of the chocolate. Once all of the tiramisus are unwrapped, top them with whipped cream and chocolate pearls or other decorations.