Preheat your oven to 350°F (175°C) and grease a Bundt cake pan with butter and a light dusting of flour.

In a medium bowl, whisk together flour, cocoa powder, baking powder, and salt.

In a large mixing bowl, cream together the butter and sugar using an electric mixer until light and fluffy.

Add eggs one at a time, beating well after each addition. Mix in vanilla extract.

Gradually add the dry ingredients to the creamed mixture, alternating with the milk, starting and ending with the dry ingredients. Mix until just combined.

Pour the batter into the prepared Bundt pan, smoothing the top with a spatula.

Bake in preheated oven for 45-50 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cake to cool in the pan for 15 minutes, then turn out onto a wire rack to cool completely.

Melt the semi-sweet chocolate chips with ¼ cup of heavy cream in a heatproof bowl over a pot of simmering water, stirring until smooth. Repeat with white chocolate chips.

Once the cake is cool, drizzle the melted semi-sweet and white chocolate over the top. Sprinkle with chopped milk chocolate bars.