Add the dry ingredients to the butter mixture gradually, starting and finishing with the dry ingredients and alternating with the milk. Blend until barely mixed.
Put Together and Bake:
Using a spatula if necessary, distribute the cake mixture evenly over the pineapple rings in the tart pans.
When a toothpick put into the middle of the cakes comes out clean, bake the tart pans for 25 to 30 minutes in a preheated oven placed on a baking sheet.
Give the cakes five minutes or so to cool in the pans.
Flip and Present:
To remove the cakes from the pans, run a knife down the sides of each cake.
After covering each tart pan with a plate, gently flip the cakes over onto the plates.
Serve hot, and feel free to garnish with a dusting of powdered sugar.
Savor each of your unique upside-down pineapple cakes!