In a large bowl beat brown sugar, oil, sour cream, egg and vanilla - set aside
In a medium bowl mix flour, cocoa, espresso, baking soda, salt and pepper
Add flour mixture to wet mixture and mix well
Refrigerate dough for 2-3 hours or if you are in a pinch you can also place the dough in the freezer for about 1/2 hour to firm up quickly.
Preheat oven to 350 degrees
Place powdered sugar in small bowl
Roll dough into 1" balls then roll generously into powdered sugar
Line cookie sheet with parchment paper and bake for about 10 minutes or until tops of cookies feel firm to the touch Don't over bake. They are done when they look a little flatter and crinkled. Remove from oven.
Let cookies cool on the baking sheet for about 2 minutes and then gently move to a wire rack to cool completely.
Cool completely on a wire rack. Store in an airtight container for up to 5 days or freeze for up to 3 months.
Spice it up by swapping out the black pepper for cayenne pepper.If you don't have instant espresso on hand you can also use regular instant coffee.