Preheat the oven to 190 °C (375 °F) conventional oven (top and bottom heat).
For the brownie batter, break the 200 g dark chocolate into small pieces and slowly melt it with 150 g butter over a double boiler. Stir the chocolate and butter into a smooth mixture. Let it cool a little.
Gradually add 120 g sugar and stir it in with a whisk.
Add the 3 eggs one at a time and stir them in as well.
Finally, briefly stir in 40 g all-purpose flour and 30 g ground almonds.
Pour the finished batter into a springform pan lined with parchment paper or into a tart pan (26 cm diameter) and smooth the top.
Bake in the preheated oven for about 20 - 25 min.
Let the base cool briefly.
Peel the 2 bananas and halve them lengthwise.
Place them flat side down on a cutting board and brush them all over with the juice of 0.5 lemon.
Cut the bananas into diagonal strips and arrange them on the cake.
Melt the 50 g milk chocolate couverture over a double boiler and drizzle it over the bananas with a small spoon.
Let the couverture set and enjoy.