Preheat the oven to 350°F (175°C). Grease a 9-inch springform pan. If you like, first line it with parchment paper.
Whisk together the flour, baking powder, and salt. Set aside.
In a large bowl, beat the butter and sugar with an electric mixer on medium speed until light and fluffy. (This should take about 3-4 minutes.)
Beat in the eggs, one at a time, mixing well after each addition. Stir in the vanilla extract and lemon zest.
Mix in the ricotta cheese until just combined.
Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Be careful not to over-mix.
Pour the batter into the prepared pan and smooth the top with a spatula. Bake for 45-50 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely before serving.
Notes
To store: Place in an airtight container at room temperature up to 2 days or in the refrigerator up to 5 days.
To freeze: Wrap well in plastic wrap and either wrap again in foil or place in a freezer-safe container for up to 2 months.