Heat the oven to 350°F and coat every well of two regular-size muffin tins generously with cooking spray. Pay particular attention to the bottom edges, where the soft cookie layer meets the pan.

Mix the brownie batter using the directions on its package, then set it beside the muffin tins. It should be ready to pour once the cookie and candy layers are in place.

Separate the refrigerated cookie dough and press a portion across the bottom of each well. A fairly even layer gives each peanut butter cup a steady base.

Place one unwrapped peanut butter cup on the dough in each well. Each cup should sit within its well without leaning against the side.

Spoon brownie batter over the candy until it is covered, stopping when each well is about three-quarters full. Leave space above the batter so it can rise without spilling over the rim.

Bake for 18 to 20 minutes at 350°F. The brownie tops should show cracks and stay still rather than jiggle when the pan moves gently.

Let the brookies cool in the pans, then ease each one out gently with a fork. They are ready to lift when the edges hold their shape and the bottoms no longer feel too soft to support them.