These rich and chewy Texas sheet cake cookies are a fun riff on the classic cake recipe. Made with a boxed cake mix and covered in a homemade chocolate icing, the cookie dough is super easy to make.
Line a baking sheet with parchment paper or a silicone baking mat.
In a large bowl mix the cake mix, eggs, and oil until well combined. The dough will be thick.
Scoop about 1 tablespoon of batter onto the prepared baking sheet, leaving 2 inches between the dough balls.
Bake for 7-8 minutes, until the outer edges are barely set and middle is still soft.
Cool cookies for 5 minutes on the baking sheet before moving them to a cooling rack. Allow to cool for 5-10 more minutes before frosting cookies - you want the cookies to be warm but not hot when you frost them.
Icing
In a saucepan over Medium heat, whisk butter, cocoa powder, and milk until the butter is melted and mixture is smooth.
Remove from heat and whisk in powdered sugar until smooth.
Spoon warm icing over each cookie, making sure they are evenly covered.
Allow icing to set (harden) about 30 minutes before eating or storing.
Notes
Don't overbake the cookies or they'll be hard.
Can add chopped pecans or pecan halves to freshly iced cookies - do this before the icing sets up.
After frosting has set, store cookies in an airtight container on the counter for up to 4 days. Can also be stored in the refrigerator.
To freeze: store unfrosted cookies in a freezer-safe container for up to 2 months. Defrost overnight in the frig and add icing after they've thawed.