Preheat oven to 350° F.
Line a loaf pan with parchment.
Whisk together the flour and baking powder.
In bowl of mixer, cream the butter and sugar together until light and creamy.
Add the egg and vanilla and beat until combined.
With mixer on low, slowly add in the flour and baking powder.
Once the flour is incorporated bring the speed up to medium and mix until well combined.
Set aside. Move batter to separate bowl if you only have one mixing bowl.
For the chocolate cake, first whisk the cocoa and baking powder into the flour.
In bowl of mixer, cream the butter and sugar together until light and creamy.
Add the egg, vanilla, coffee and two tablespoons of flour mixture (this stops the butter from looking curdled) and beat until combined.
With mixer on low, slowly add in the flour mixture.
Once the flour is incorporated bring the speed up to medium and mix until well combined.
Using an ice cream scoop or a large spoon, alternate scoops of vanilla and chocolate batter into the prepared pan. Do this until all the batter is used.
Swirl the batter by running a knife through the batter.
Bake for 55-60 minutes or until toothpick inserted in the center comes out clean.
