Preheat oven to 350. Line baking sheets with parchment paper.
Stir the hot water and espresso powder together. Set aside to cool.
Whisk the flour and baking powder together to combine.
In a large bowl, cream the butter and sugars together for several minutes until combined, and no lumps of butter remain.
Beat in the egg. Add the espresso mixture and the vanilla. Beat until combined.
On low speed, add the flour mixture in three additions. Scrape bottom and sides of the bowl as needed.
Wrap the dough in plastic wrap and chill for 30 minutes before rolling.
Roll to ⅜" on a floured surface using a floured rolling pin.
Place on cookie sheet and freeze shapes for 5-10 minutes before baking to prevent spreading.
Bake for 9-13 minutes depending on cookie size.
Let rest on the sheet for 1-2 minutes, then remove to a wire cooling rack to cool completely.
