Preheat the oven to 350 degrees. Remove the sliders from the package and use a
knife to cut a circle out of the center of each bun. Press the center of the bun down to make a hole on the top of each bun.   

Brush the top and inside of each bun with butter and sprinkle the garlic powder over the top. 

Add a small amount of cheese to the inside of each hole in the buns.Press one frozen meatball into the top of each bun.

Top the meatball with a spoonful of marinara sauce. 

Sprinkle the remaining shredded cheese over the top of each meatball.  

Bake in the preheated oven for 15 to 20 minutes, until the meatballs are heated through and the cheese is melted.