Chocolate mound cake with bananas and stracciatella cream

Take the butter out for about 30 minutes to soften. Keep the cream and mascarpone in the refrigerator. Preheat the oven to 180°C with conventional top and bottom heat. Line the bottom of a springform pan measuring 22 cm across and about 6 cm deep with parchment paper. Use 5 g of the weighed butter to lightly grease the sides, and reserve the remaining 95 g for the cake.

Put 95 g of softened butter in a bowl. Add all the white sugar and the salt. Beat with an electric mixer for about 4–5 minutes, until lighter and fluffy. Scrape down the sides of the bowl with a spatula.

Add the eggs one at a time, beating briefly after each. In a separate bowl, mix all the flour, cocoa and baking powder, then sift into the butter mixture in two batches, alternating with the weighed milk. Mix on low speed just until combined. Scrape all the batter into the pan and smooth the top.

Bake on the middle rack for about 30–35 minutes, until the cake springs back and a skewer inserted in the center comes out without raw batter. Let the pan stand for 10 minutes, then carefully remove the ring and transfer the cake to a wire rack. Allow about an hour of cooling in total, until completely cold, before adding the cream filling.

Place the completely cold cake base on a plate. Use a spoon to hollow out the top to a depth of about 1–1.5 cm, leaving a bottom about 1 cm thick and a rim about 1.5 cm wide. Do not break through the bottom. Put all the removed cake into a bowl and crumble it finely with your fingers; you will use every soft crumb on the dome.

Finely chop all the chocolate. Put the cold mascarpone in a large bowl, pour in the cold cream and add all the powdered sugar. Start whipping on low speed, then increase to medium. Whip until the filling thickens and holds the marks of the beaters; stop before it becomes grainy. Fold in all the chocolate pieces with a spatula.

Peel the bananas and weigh out 250 g of flesh. Cut them in half lengthwise and arrange them flat side down in the hollowed cake. Trim the halves if needed and use the cut pieces to fill any gaps, including the entire weighed amount.

Spoon all the stracciatella filling over the bananas. Spread it to the cake's rim with a spatula and shape the center into a rounded dome. Smooth the surface, keeping the filling noticeably higher in the center than at the edges.

Cover the filling with all the reserved cake crumbs, starting at the bottom of the dome. Gently press them into the cream with your hand and gather any crumbs from the plate to cover the remaining patches. Use the entire amount while keeping the mound rounded.

Refrigerate the cake for at least 2 hours to let the filling set. Cut into ten servings and serve chilled. Keep any remaining cake covered in the refrigerator and use within two days.