Prep your pan. Heat the oven to 350°F (175°C). Grease a 9-inch springform pan or cake pan, then line the bottom with parchment. This helps prevent sticking and makes unmolding easier.

Combine dry ingredients. In a medium bowl, whisk almond flour, baking powder, baking soda, and salt. Break up any lumps so the batter stays smooth.

Cream the butter and sweetener. In a large bowl, beat the softened butter and erythritol until light and fluffy, about 2–3 minutes. This step helps with lift and texture.

Add ricotta and flavorings. Beat in the ricotta until creamy. Mix in vanilla, lemon zest, and lemon juice. If using almond extract, add it here.

Add the eggs, one at a time. Beat in each egg fully before adding the next. Scrape down the sides so everything blends evenly.

Fold in dry ingredients. Add the almond flour mixture and stir until just combined. The batter will be thick and silky, not runny.

Pan and top. Spread the batter into the prepared pan and smooth the top. Sprinkle sliced almonds if you like a little crunch and a pretty finish.

Bake. Bake for 35–45 minutes, or until the center is set and a toothpick comes out mostly clean with a few moist crumbs. The top should be lightly golden.

Cool properly. Let the cake cool in the pan for 15 minutes, then release the springform or turn out onto a rack. Cool completely before slicing to help it set.

Optional glaze or dusting. Whisk powdered erythritol with a squeeze of lemon juice and a splash of water to make a quick glaze. Drizzle over the cooled cake, or simply dust with powdered sweetener.