We will start by preparing the cake. For it, preheat the oven to 180 degrees centigrade with heat up and down. We line a tray with baking paper.
Put the milk in a bowl and add the lemon juice. we let it rest during 15 minutes until we see that the milk is slightly lumpy. We reserve this mixture.
Then, in a bowl, add all the ingredients, including the milk, stir with a whisk and pour the mixture into 18-centimeter pastry rings or even, if it is easier for you, spread on top of the baking paper on the baking tray. Bake for 15 or 20 minutes. Cool completely.
For the mascarpone filling. Put the cream, sugar and agar agar in a saucepan and stir until integrated. Heat the mixture and cook for 2 or 3 minutes to activate the agar agar. Pour this mixture over the white chocolate and stir until it has melted and integrated with the cream. Add the mascarpone cheese and beat with a mixer until the mixture is creamy.
For the bath syrup. Mix the sugar with strong coffee and heat until the sugar dissolves. Add the coffee liqueur. We booked.
To assemble the cake. Cut a disc of sponge cake 18 centimeters in diameter and another 16 centimeters to put inside the cake.
We place it in a ring with a plastic acetate strip around it to facilitate unmolding, or in a removable mold of 18 centimeters in diameter, the largest sponge cake base. We brush it well with the syrup. Pour a little more than half of the mascarpone cream on top.
Place the small sponge disc in the center of the ring, soak it again with the syrup and put the rest of the mascarpone cream on top, smoothing the surface with a spatula. We leave eight hours in the freezerwe remove the strip of plastic acetate or unmold and then we put it in the fridge to defrost before serving.
Just before presenting it, we sprinkle it with cocoa powder and decorate it with some coffee beans.