Let’s dive into the process of creating these bars, a journey I hold dear to my heart:

1. Preheat your oven to 350°F (175°C), setting the stage for baking magic.
2. In a large mixing bowl, cream together the butter, granulated sugar, and brown sugar until light and fluffy. I always recall Mama Lou’s gentle reminder to take my time with this step, ensuring the sugars and butter meld perfectly.
3. Add the eggs one at a time, followed by the vanilla extract, mixing until fully incorporated. This step always brings back memories of Ouma cracking eggs with precision, her laughter ringing in the air when a rogue shell piece made its way into the mix.
4. In a separate bowl, whisk together the flour, cream of tartar, baking soda, and salt. Gradually add this to the wet mixture, stirring gently until just combined.
5. Spread the dough evenly into a greased 9×13-inch baking pan. This part always felt like an art form, smoothing the top with care.
6. Combine the cinnamon and additional sugar, then sprinkle generously over the dough. The cinnamon-sugar topping was always my favorite part, a tactile memory of sprinkling it with eager hands.
7. Bake for 20-25 minutes, or until the edges are golden and the center is set. The anticipation during these minutes is a story in itself, filled with the comforting aroma and the promise of something delicious.
8. Allow the bars to cool in the pan before cutting into squares. This waiting period, though challenging, was always worth it, as Mama Lou would say.