Preheat oven to 350 F/177 C. Prepare baking pan(s): grease and flour a 13 x 9 or two layer cake pans; place cupcake papers in two muffin pans.
Put all dry ingredients into the mixing bowl. Add the butter and mix well until the ingredients look sandy.
Add yogurt, milk, and vanilla into the dry ingredients and mix well. Then add eggs one at a time, until combined. Turn mixer on medium speed, and mix for 2 minutes.
Pour batter into prepared pan(s). Bake cakes for 30-35 minutes, cupcakes for 20-22 minutes, until a toothpick inserted into the middle comes out clean. Allow the cakes to cool completely before frosting.