Pre-heat oven to 350 degrees. Spray muffin tins well with cooking spray. Melt butter and sugar together on top of the stove.
Add 1 tblsp. sugar mixture to each muffin cup. Next, put in 1 tblsp. crushed, drained pineapple, or pineapple slice in bottom of each cup.
In a large bowl, mix cake mix, pudding mix, eggs, oil, juice, including juice from cans, and milk with mixer. Fill cups 1/2 to 3/4 full with batter.
Bake in 350 degree oven for 25 minutes. Remove, and let cool for 10 minutes. Run a knife around the edges to loosen cupcakes from cups before removing from pan. Turn cupcakes upside down on a platter, and add cherries.
NOTE: If you use 1 regular 12 cup muffin tin, and 1 large 6 cup muffin tin, you will get 18 cupcakes. If you use 2 regular sized muffin tins, you will get 24 cupcakes. The pineapple slices fit better in the large muffin tin, and the crushed pineapple works for the regular sized muffin tin. The choice is up to you. You can use all slices, or all crushed pineapples.