Preheat oven to 350°. Line baking sheets with parchment paper.
Be sure to melt the butter and chocoalte chips and allow them to cool.
In a small bowl whisk eggs, then stir in melted butter, and vanilla, until thick and blended.
In the bowl of a mixer add the flour, sugar, cocoa, and baking powder and mix until fully combined.
Pour in the egg/butter mixture and mix on low to combine, then medium to medium-high speed until the dough fully blends, the dough will be smooth and pull away from the sides of the bowl.
Roll the cookie dough into a ball. Cut in half and roll out, to avoid dry cookies I don't usually use flour. I roll the cookie dough between, parchment paper plastic wrap, waxed paper, or on a chopping block with 1 layer on top. Then roll the cookie dough to 3/8" thick (if you want thinner cookies roll thinner and adjust the baking time as they'll bake quicker.)
Cut with desired shape cookie cutter and place on parchment-lined baking sheets.
Bake for 10-12 minutes depending on cookie size. The cookies will be firm and set, but will not be crisp. These cookies do not spread, but be sure to allow plenty of space in between each cookie so they bake properly, and overcrowded baking sheet is the reason a lot of cookies will not bake properly.
Remove each baking sheet from the oven when the cookies are finished baking and allow all the cookies to cool completely on the baking sheets. Avoid moving them so they don't break or get messed up.
Apply icing or frosting onto completely cooled cookies or serve plain. They are great with or without frosting/icing.