CHOCOLATE BANANA SWISS ROLL

Ingredients
SPONGE:
- 5 eggs, separated
- 2 Tbsp sugar
- 2 Tbsp all-purpose flour
- 2 1/2 Tbsp cocoa powder
- 2 tsp baking powder
- 2 tsp vanilla extract
FILLING:
- 3 eggs
- 150 g sugar (3/4 cup)
- 200 g chocolate, 43 % cocoa (7 oz)
- 1/2 tsp instant coffee powder
- 2 tsp vanilla extract
- 1 Tbsp rum (or rum flavoring)
- 150 g butter (1 1/3 stick or 10 1/2 Tbsp)
- 3-4 large bananas
OPTIONAL:
- 200 ml whipping cream (a little bit less then a cup)
- chocolate sprinkles
Instructions
1. SPONGE: Combine flour, cocoa powder and baking powder.
2. Whisk egg whites and set aside.
3. Mix egg yolks with sugar until pale. Add vanilla extract, egg whites and flour-cocoa mixture. Slowly and gently stir with a spoon (do not use mixer).
4. Transfer the mixture to a sheet pan lined with baking paper (my pan is 12×13 inches or 30×33 cm large). Bake in 180 C (350 F) oven for about 15 minutes.
5. Roll the sponge together with baking paper and let cool.
6. FILLING: Mix eggs with sugar over water bath (or a very low heat). Cook until mixture reaches 80 C (175 F). Be careful, because if you continue cooking over this temperature, the eggs will coagulate (scramble).
7. Add chocolate, coffee powder, vanilla extract and rum. Let cool to room temperature.
8. Mix butter until fluffy. Combine butter with egg-chocolate mixture.
9. ASSEMBLING: Peel off the baking paper from the sponge. Place on a cling film (it will help you roll the cake easier). Spread the cake with 1/2 of the chocolate filling. Place two bananas on 2 opposite sides of the cake. Slowly roll each end toward center (see video).
10. Spread remaining filling on the top of the cake roll. Use a fork to create lines (if not using whipped cream).
11. OPTIONAL STEP: Before serving, take the cake out of refrigerator and let come to room temperature. Whip cream until stiff. (If cake will wait for your guests for longer time, consider stabilizing whipped cream.) Sprinkle with chocolate sprinkles.