In a 10-inch cast iron skillet, melt the butter over very low heat.
Meanwhile stir the flour, baking powder, and salt together in a bowl. Set aside.
To the melted butter, add the brown sugar. Stir together and let the brown sugar dissolve.
Remove from heat.
In a mixing bowl, beat together the shortening and sugar until creamy.
Add in the eggs and mix well.
Mix in half of your dry ingredients. Then add in the milk and finally the remaining dry ingredients.
Stir in the vanilla. Beat for just a minute until smooth.
Press any excess liquid from the pineapple and then spread the pineapple over the bottom of the skillet.
Gently pour the batter over the top and smooth the top.
Bake for 40-50 minutes, or until it tests done with a toothpick.
Allow it to cool a couple minutes in the skillet, then turn it out onto a platter.
Cool completely and enjoy!
Notes
If you do not have a cast iron skillet, this can be made in a round cake pan. Simply melt the butter before adding it to the pan. Do the same from there.