Preheat oven to 350 degrees F. Place ¼ cup butter in a 9-inch round pan. Put pan in the oven until the butter melts. Sprinkle the brown sugar in an even layer over the melted butter.
Place one whole pineapple ring in the center of the pan. Cut the other pineapple slices in half, and arrange them in a fanned manner. You will use about 6 whole slices, or 12 halves, to cover the bottom of the pan. Place a cherry in the center of each pineapple slice.
In a mixing bowl, beat butter for 2 minutes. Add sugar and vanilla and continue beating with electric mixer until blended. Add eggs, beating well. Combine flour, baking powder and salt in a small bowl. Add to the butter mixture, alternating with the whole milk. Beat for 3 minutes after all is added.
Pour cake batter into cake pan and spread evenly over the pineapple. Bake for 50 minutes or until a toothpick comes out clean and top is browned.
Immediately after removing from oven, place a cake plate or platter on top of the cake pan. Flip the plate and pan upside down. Leave pan over cake for a couple of minutes allowing the brown sugar mixture to drizzle over cake. Remove pan. Serve warm.
Loosely cover and store cake in the refrigerator for best results.
Pineapple Slices: I like to cut my pineapple rings in half before arranging them in the pan. I find this gives you more pineapple taste per bite. If you prefer, you can also keep them in ring shape and arrange them however you like.
How to store: This cake keeps best stored in the fridge. Cover it loosely with plastic wrap, foil or a cake cover to keep it moist. I do not recommend freezing pineapple upside down cake.
Cake Pan: You'll need a round cake pan, that is deep enough to bake this treat. I bought mine on Amazon- THIS ONE IS PERFECT.