1 ½cupsemisweet or dark chocolate chips(255g) plus additional for topping, if desired
Instructions
Preheat oven to 350F (177C) and line cookie sheets with parchment paper. Set aside.
In a large bowl, combine your melted, cooled butter, and sugars. Stir until well-combined.
Add egg and egg yolk, stir well.
Stir in vanilla extract. Set aside.
In a separate, medium-sized bowl, whisk together dry ingredients (flour, cocoa powder, cornstarch, baking powder, salt, baking soda, and instant coffee grounds.
Gradually add dry ingredients to wet, stirring well until ingredients are well incorporated.
Stir in chocolate chips.
Drop cookie dough by rounded 1 ½ Tbsp-sized scoops onto cookie sheet. Use your fingers to gently form the dough so that it is slightly higher than it is wide (think egg-shaped rather than round).
Bake on 350F (177C) for 10 minutes (cookies should still seem slightly underbaked in centers, this is OK, allow them to cool completely on pan and they will finish cooking but still be soft)
If desired, gently press additional chocolate chips into the tops of cookies shortly after removing from the oven.
Video
Notes
*NOTE: I made these cookies multiple times and never needed to chill the dough. However, if your cookies come out too flat/paper thin, try chilling the dough 15-30 minutes before baking