Adjust oven rack to middle position and preheat to 325°F (160°C). Using nonstick baking spray, lightly grease a 9-inch aluminum cake pan and line with parchment paper .

In a large bowl, whisk together cake flour, almond flour, baking powder, baking soda, and salt to combine; set aside.

In the bowl of a stand mixer fitted with a paddle attachment, combine granulated sugar, light brown sugar, butter, and lemon zest. Mix on medium speed until incorporated, about 1 minute, then increase speed to medium-high and beat until fluffy, about 3 minutes, stopping to scrape the bowl and paddle with a rubber spatula halfway through.

Reduce speed to medium-low and add eggs one at a time, letting each fully incorporate before adding the next. Add ricotta and increase speed to medium, beating until incorporated, about 1 minute. (The mixture may look broken, this is okay.) Stop the mixer and add the flour all at once. Mix on low speed for 15 seconds to just incorporate, then increase speed to medium and beat until batter is well-combined and smooth, about 30 seconds.

Using a flexible spatula, transfer batter to the prepared cake pan and smooth the top.

Bake until top of the cake is golden brown and a cake tester or toothpick inserted into the center of the cake comes out clean, with just a few moist crumbs attached, 65 to 75 minutes.

Cool cake directly in the pan for 1 hour, then run an offset spatula or butter knife around the edges to loosen. Invert onto a large plate or wire rack, peel off the parchment, and flip cake right side up. Allow cake to cool completely.

Using a fine-mesh sieve, sift powdered sugar over cake. Slice and serve.