For a subtly different flavor substitute a fruit based yogurt, like raspberry, for the plain yogurt.
3/4 cup butter, room temperature
1 cup brown sugar
1 teaspoon vanilla extract
1 tablespoon hot water
1/2 cup plain Greek yogurt
2-1/2 cups all-purpose flour
1 tablespoon espresso powder
1/4 cup unsweetened cocoa powder
1 teaspoon baking soda
1/2 teaspoon salt
1/4 cup granulated sugar
Preheat the oven to 350 F.
Cream the butter and brown sugar together until light and fluffy. Add the egg and vanilla. Mix well. With the mixer on low add the hot water then the Greek yogurt, scraping down the sides of the bowl as necessary. Add the flour, espresso powder, cocoa powder, baking soda, and salt. Mix until well combined.
Put the granulated sugar into a small bowl and set it aside. Gently roll the dough into 1" size balls and roll each ball in the granulated sugar to coat. To make more uniform sized cookies, I like to use a small 1 oz ice cream style scoop. Place sugar-coated balls on a parchment lined baking sheet and bake for 10 to 12 minutes. Remove from the oven and place the baking sheet on a wire rack to cool. Freezes well.