I found this recipe on Two Peas and Their Pod. They are very good, and very fudgy. There is no egg, but the dough is not crumbly. Don't use a cookie scoop to scoop out the dough, or else the will turn craggy and look not so appealing. Roll them into balls. No need to flatten them.
1-1/4 cups flour
1 teaspoon baking powder
1/2 teaspoon salt
2/3 cup dutch-process cocoa-make sure to use dutch process for a rich/dark flavor
1/2 cup (1 stick) unsalted butter, cubed and room temp
1/2 cup white sugar
1/2 cup dark brown sugar
1-1/2 teaspoons vanilla
1/3 cup milk
1 (12-oz) bag of Nestle Dark Chocolate & Mint Chips (Original recipe calls for Guittard Mint Chips, but I can't find them anywhere, so I used the Nestle chips)
Stir together the flour, baking pwd, salt and cocoa and set aside. Cream the butter and sugars until light and fluffy. Add the vanilla, mixing in well. Add the flour mixture and milk alternately, until combined. Add the dark chocolate and mint chips. Chill for at least 15 minutes. Bake on ungreased cookie sheets 325 degrees for 14 - 15 minutes. Cool completely on the cookie sheet so that they can firm up. Store in an airtight container.