Grease two 8-inch round cake pans and line the bottoms with parchment paper if you have it. This helps prevent sticking.
In a small bowl, mix the flour, baking powder, and salt. Set aside.
In a large bowl, whisk the milk, orange juice, orange zest, yogurt, vanilla, eggs, and sugar. Sift the dry ingredients into the wet ingredients. Whisk gently just until no dry flour remains. Do not overmix.
Divide the batter evenly between the prepared pans and bake for 20-25 minutes, or until the tops spring back lightly when pressed, and a toothpick inserted in the center comes out clean or with a few moist crumbs.
Let the cakes cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely before frosting.
In a large bowl, beat the cream cheese and butter together until smooth and fluffy. Add the powdered sugar, orange zest, orange juice, and a pinch of salt. Beat until smooth and spreadable. Taste and add more powdered sugar if you want it sweeter.
Spread icing over one cooled cake layer, place the second layer on top, and frost the top and sides as desired. Or serve as two single-layer cakes.
Notes
This recipe makes two 8-inch round cake layers.The orange cream cheese icing is lightly sweetened. Add powdered sugar gradually if you prefer a sweeter frosting.Let the cake cool completely before frosting to prevent the icing from melting or sliding.