In a large mixing bowl combine flour, baking powder, sugar, and salt.
In a separate bowl, zest and juice the lemon.
Add the melted butter, 5 eggs, and vanilla. Beat until well combined.
Slowly combine the wet ingredients to the dry ingredients alternating with pouring the milk in.
Once combined, add the lemon yogurt.
Mix all ingredients until no longer lumpy.
Pour into a lined cupcake pan.
Bake at 350 for about 18 minutes.
Cream Cheese Frosting:
Beat cream cheese until smooth.
Add in butter and beat until smooth.
Add powdered sugar a little at a time.
Beat until incorporated.
Add vanilla.
Fill a piping bag with frosting and decorate as desired!
If making the rainbow cupcakes- cut the rainbow candies in half, fold into a half moon and place on top of frosting!