On the right, the way the cookies should look. On the left….NOT! We had an impromptu cookie CSI session: what could have gone wrong? Was the butter at room temperature? Yes. Did we measure the cocoa powder like flour (spooned and not scooped into the measuring cup)? Yes. Which oven did we test in? Which baking sheets did we use? Everything should have been right. And then it hit us: is the baking powder out-of-date? One look at the bottom of the tub confirmed our suspicion. Into the trash it went, Heather made a new batch using fresh baking powder and all is well! So today’s tip is especially heartfelt: before cooking with baking powder, do this quick test on your supply: add 1 tsp baking powder to 1/2 cup warm water. If it fizzes and bubbles, it’s still active. If not, toss it out and buy fresh.