This did not come out as expected, but it was still yummy. The mocha topping was heavier than the cake batter, so it sank, creating dark pits of mocha-salted deliciousness.
1/2 C (1 stick) butter
1-1/2 C flour
1/2 C brown sugar
1/2 C white sugar
1-1/2 t baking powder
1/2 t cinnamon
1/2 t salt
Mix ingredients together in a large bowl. Remove 1/2 C of this mixture to another, smaller bowl.
To the large bowl, add:
1 egg
1/2 C milk
Pour this mixture into a greased 8×8 pan. (Sometimes, I used a heart-shaped pan as a surprise for my loved one.)
To the small bowl, add:
2 T used coffee grounds
1/2 C white sugar
1/4 C cocoa powder
Spread spoonfuls of this topping over the cake and sprinkle with coarse sea salt.
Bake at 350 F for 25 minutes, or until done.