Preheat the oven to 350°F (180°C). Grease a 10-inch bundt pan with butter and flour it.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
In a large bowl, beat the butter and sugar until light and fluffy, about 2-3 minutes. Add the eggs one at a time, beating well after each addition.
Add the ricotta cheese and vanilla extract and mix until well combined.
Add the lemon and orange zest and juice and mix until incorporated.
Alternate adding the dry ingredients and milk to the wet ingredients, mixing just until combined after each addition.
Pour the batter into the prepared bundt pan and bake for 50-60 minutes, or until a toothpick inserted in the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then invert it onto a wire rack to cool completely.
Dust the cooled cake with powdered sugar before serving.
