Preheat oven to 325°F (163°C). Grease and flour a 9x5-inch loaf pan or a bundt pan.
In a large mixing bowl, beat the butter and sugar together until light and fluffy, about 3 minutes.
Mix in the eggs one at a time, beating well after each addition. Stir in the vanilla extract.
In a separate bowl, whisk together flour, cocoa powder, baking powder, and salt.
Gradually add dry ingredients to the wet mixture, alternating with milk, beginning and ending with the flour mixture. Mix until just combined.
Pour batter into the prepared pan and smooth the top.
Bake for 60-70 minutes, or until a toothpick inserted in the center comes out clean.
Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
For the optional glaze: Heat the heavy cream until warm, then pour over the chocolate chips. Stir until smooth, then mix in vanilla extract. Drizzle over cooled cake.
Slice and serve as is or with a scoop of ice cream!
Notes
For a richer flavor, use dark cocoa powder. Store leftover cake in an airtight container at room temperature for up to 3 days.