Preheat oven to 350° and place rack in the middle of your oven.

Sift together the flour, cocoa, baking powder and salt. Set aside.

Place mint and sugar into a food processor and blend until it resembles coarse wet sand.

In a sauce pan over the lowest setting melt the chocolate and butter. Stir often to avoid scorching and remove when only a few lumps remain. Stir until completely melted then pour into a large bowl. Add the mint sugar to the chocolate and stir. When the chocolate has cooled a tad, gradually add eggs and vanilla and stir.

Add a third of the dry ingredients to the chocolate mixture, mix by hand. Repeat until all the dry ingredients are incorporated. Cover with plastic wrap and refrigerate for one hour.

Using a tablespoon or small ice cream scoop, measure and roll into uniform balls. Roll the cookie balls in granulated sugar and then powdered sugar, then place the cookie balls an inch apart on a lined or greased, rimmed baking sheet.

Slide into oven and bake for 10-12 minutes depending on your oven. Remove and let cool on the pan for 5 minutes then remove to cooling rack to finish. Makes 3 dozen cookies.