Preheat oven to 170°C (340°F). Grease your bundt pan with butter and dust with breadcrumbs if desired.
1 tablespoon butter, 1 handful breadcrumbs
Cream the room-temperature butter with ¾ of the sugar (150g / ¾ cup) until light and fluffy. Mix in a quarter of the sifted flour, then beat in the 2 whole eggs one at a time. Add the 3 egg yolks and mix until smooth.
150 g unsalted butter , 200 g granulated sugar, 5 eggs
Combine the remaining flour, cocoa powder, baking powder, and salt. Add the dry mixture with the milk, vanilla, and almond extract to your butter mixture. Beat until you have a smooth, rich batter.
50 g unsweetened cocoa powder, 1 ½ teaspoon baking powder , ½ teaspoon salt, 60 ml milk, 1 teaspoon vanilla extract, 1 teaspoon almond extract, 180 g all-purpose flour
In a spotlessly clean bowl, whip the 3 egg whites to soft peaks. Gradually stream in the remaining sugar (50g / ¼ cup) and whip to glossy, stiff peaks.
Gently fold the billowy egg whites into your chocolate batter, keeping it light and airy.
Melt your three chocolates separately in double boilers or microwave. Swirl half of each melted chocolate through the batter to create beautiful marbled streaks.
100 g dark chocolate, 100 g milk chocolate , 100 g white chocolate
Pour into your prepared pan and bake for 45 minutes, until a toothpick comes out clean. Let it rest in the pan for 10 minutes, then turn out onto a cooling rack.
Once completely cool, drizzle the remaining melted chocolates over the top in artistic swirls.