Marble roll with banana chocolate cream

for biscuit:

eggs 4 pcs.
sugar vanilla 1 pc.
vegetable oil 4 tbsp.
sugar 4 tbsp.
flour 4 tbsp.
water 1-2 tbsp.
cocoa powder 1 tbsp.
Instant coffee 1 tsp.
baking powder 1/2 tsp.
salt 1 pinch

for cream:

sour cream 40% 200 g
chocolate 100 g
thickener for cream 1 pc.
bananas 1 pc.
sugar powder 1 tbsp.
cognac / rum 1 tsp

Prepare the dough by first whipping the proteins with sugar and a pinch of salt. Separate the yolks from whites separately, also with sugar, add vanillin. In this mixture gradually add vegetable oil without a smell. Connect both masses. In the egg mass, mix the sifted flour with the baking powder. Stir gently, try not to lose volume, the dough should turn out to be airy, light.

Separately mix cocoa and instant coffee, dilute with boiling water. Cover a small baking tray with baking paper, grease a little with vegetable oil. Lay out two-thirds of the dough in an even layer. The remaining dough is mixed with the cocoa-coffee mixture, mix. Spread a tablespoon on a light dough in the form of blots, they are a little "washed" with a wooden stick, you can use a toothpick.

The oven at 180 degrees for 15 to 20 minutes. Bake the layer quickly overturned on a kitchen towel and roll hot into a roll. Leave curled in a towel until it cools. To prepare a cream: to beat up sour cream with powder, to add a thickener for cream. Melt the chocolate in a water bath separately. Ripe banana peel and mash with a fork in puree, combine with chocolate, pour in brandy. Mix the mixture mixed until smoothly with sour cream. Cool the cooled marble roll with the resulting cream and fold again. Cool and serve to the table.