Preheat oven to 350°F (175 degrees C). Prepare (use pan release or baking spray and line with parchment) three 8-inch by 3-inch round cake pans. (If you use a shorted pan it could spill over)
Whisk together the cocoa and boiling water. Set aside to cool.
Sift together the flour, baking soda, salt, and baking powder and set aside.
In the bowl of stand mixer fitted with paddle attachment, cream together the butter and sugar until light and fluffy, 2-3 minutes.
Beat in the eggs, one at a time, then stir in the peppermint.
Add the dry ingredients alternately with the cocoa mixture. Mix only until combined.
Divide evenly between the three prepared pans, and tap on the counter to settle.
Bake for 18 to 22 minutes in the preheated oven, until a toothpick inserted comes out clean, and the cake pulls away from the sides of the pan.
Cool cakes on a wire rack.