Start by microwaving the buttermilk for 30-45 seconds or just until warmed.

Stir in coffee granules and mix until all the granules have dissolved. 

In a stand mixer or bowl, cream butter and brown sugar until light and fluffy.

Add eggs, one at a time, beating well after each addition. Followed by your vanilla. 

Combine the flour, cornstarch, baking powder, baking soda, salt and nutmeg into a small bowl and mix. 

Incorporate the dry ingredients to the wet. Add to creamed mixture alternately with buttermilk mixture, beating well after each addition.

Transfer to a greased 13x9-in. baking pan.

Bake at 350 degrees for 20-25 minutes or until a toothpick inserted in the center comes out clean.

Cool the cuppa joe caramel cake on a wire rack for 5 minutes.

Using the end of a wooden spoon handle, poke holes in the cake all over.

Pour 1/2 cup caramel topping into holes.

Spoon remaining caramel topping over cake, cool completely.

For frosting, in a small bowl, stir cocoa and coffee granules into boiling water until dissolved; cool to room temperature.

In a small bowl, cream butter and confectioners' sugar until light and fluffy.

Stir in melted chocolate and cocoa mixture until well combined.

Frost cake.

Serve and enjoy!