Cream 150 g butter, 75 g icing sugar and salt with the whisk of the hand mixer. Stir in the eggs one after the other. Stir in 200 g condensed milk. Mix flour and baking powder and finally stir in briefly
Put approx. 1/3 of the dough into a greased, floured box cake tin (25 cm long, 11 cm wide, approx. 1.6 litres capacity) and spread. Spread the biscuits over it. Bring milk to the boil. Dissolve espresso powder and cocoa powder in it, stir in cinnamon. Stir into the remaining dough. Spread the dough on the biscuits
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 45 minutes. Leave the cake to cool on a cake rack for approx. 30 minutes, then carefully remove from the edge, turn onto a plate and leave to cool for approx. 2 hours
Whip remaining condensed milk with lemon juice and cream setting agent for approx. 1 minute. Whip 75 g butter and 25 g icing sugar until creamy white. Stir the condensed milk into the butter and spread on the cake. Refrigerate again for approx. 1 hour and serve
waiting time approx. 2 1/2 hours