Instructions: Step 1: Preheat the oven to 325 degrees. Lightly grease a 9-inch round cake pan with nonstick cooking spray, line the bottom with parchment paper, and grease the parchment. Place the cake pan on top of a baking sheet. Step 2: In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside. Step 3: In a large bowl, beat the butter with an electric hand mixer or in a stand mixer fitted with the paddle attachment until smooth. Add the sugar and lemon zest and cream the mixture until light and fluffy, about 2 minutes. Scrape down the bowl with a rubber spatula.