Cut Hawaiian sweet rolls in half horizontally, and arrange the bottom halves in a 9 x 13 nonstick baking pan.
On top of the bread, even though you guys are all of the ham slices, Swiss cheese slices, and dill pickle slices. Place the top half of the rolls on each sandwich.
In a microwave, in 30-second bursts, melt butter. Once butter is melted, stir in onion powder and Dijon mustard. Brush mustard butter mixture across the top of the slider buns.
Covered with aluminum foil and bake in the oven for 10 minutes. Uncover and bake for another 10 minutes, or until slider buns are golden brown and cheese is melted.