Dancing with Knives: Wanted: Cream of tartar

Today I tried to make cookies to take to work to share with my coworkers. I had a recipe for a "skinny lemon poppy seed cookie" that I was excited to try. I only recently started to like the flavor of lemony sweets, but still cannot even think of eating lemon meringue pie, yuck. My grandma is said to make a delicious pie and family members even request she make it for family parties. But still, I want nothing to do with that lemon treat. But the cookies I decided to try.
I have had this bag of poppy seeds for well over a few months, dare I say years even. It was time to use them, and with my new found like for lemon it seemed like a winning idea to make lemon poppy seed cookies. I found a lightened up recipe and set up my stuff in the kitchen with a fresh cup of coffee. The one ingredient that I didn't have was cream of tartar, but after researching I thought I could just substitute it by adding more baking powder. Spoiler alert: it turns out that there is no good substitute for the tartar. If you don't have it, don't fake it. My cookies turned out flat, yes actually flatter than a pancake and so sad looking. However, the batter was so delicious that I will probably try to make them again and actually harness the magical powers of the tartar.
I also added crushed rosemary to the batter and will absolutely do it again the second time around. So instead of bringing my fun coworkers fresh baked cookies I just left them on the pan, flattening in the center even more like a cooling cake. Before I left for work though I peeled a cookie off the aluminum foil and tasted it and would have loved if it was fluffy. Better luck to myself next time.
My ingredients from most to least amounts added include:
corn flour (b/c this was what I had on hand), sugar, butter, flax seed meal, water, poppy seeds baking powder, salt, lemon juice and zest, and rosemary.