Preheat the oven to 350ºF. Grease and flour Bundt pan (or you could use baking spray, as I did).
Combine dry ingredients: In a medium bowl, combine the flour, baking powder and salt. Stir to blend.
Mix butter, ricotta, and sugar: Using a mixer (or by hand), cream the butter, ricotta and granulated sugar until blended, about 3 minutes — I never really go over three minutes, and it’s ok if there are some visible pieces of butter. In other words, the batter will not look entirely smooth (see photo). With the machine running, add the eggs 1 at a time.
Mix in eggs: Add the eggs 1 at a time.
Add the vanilla, zest and lemon juice until combined. Add the dry ingredients, a small amount at a time, until just incorporated. Stop the mixer and use a spatula to scrape the sides of the bowl after each addition of the dry ingredients.
Pour the batter into the prepared pan and place on middle rack of oven.
Bake for 25 minutes on 350. Lower heat, bake about another 20 minutes on 325, or until a toothpick comes out clean and the cake pulls away from the sides of the pan. I always have to lower my oven to 325 with cakes. My cakes bake too fast if I bake all the way on 350.
Invert cake: Carefully invert the cake onto your serving plate. Dust with confectioner's sugar, or make a lemon glaze with fresh lemon juice.