Preheat oven to 325 degrees
Prepare three 8-inch cake pans by coating the bottoms & sides with cake release spray.
In a small bowl, mix the milk & heavy cream. In a medium bowl, sift the all-purpose and cake flours and baking powder. Then set aside.
(Tip: IF you don't have a sifter or strainer you can mix & fluff your dry ingredients with a whisk to get the same aerated effect as sifting.)
In a large bowl, cream the butter using an electri mixer on medium speed until it's soft and light (about 2 minutes). Add sugar & salt and mix until the mixutre is light in color and fluffy (about 2 minutes)
On the low setting, mix in one-third of the flour mixture. Add half of the milk mixture & mix until just combined. Then add another third of the flour mixutre. Repeate with the remaining milk and flour mixture. Be careful no to over mix!
Pour the batter carefully into the cupcake pan
Bake 35-40 minutes, until a toothpick inserted into the center comes out clean
Let the cupcakes cool for 10 minutes