Perfect pierogies casserole from Food.com is a good recipe. Other good recipes are easy pierogi casserole from Kraft, bacon pierogi bake from MyRecipes and pierogi casserole from the Huffington Post.
Make a bacon pierogi bake by placing 1 16-ounce package of frozen pierogies at the bottom of a casserole dish. Cook 2 chopped bacon slices in a skillet. Once the bacon turns crispy, remove from the pan, and add 2 minced garlic cloves to the bacon fat. Saute the garlic for 30 seconds, then add 1/3 cup cream cheese. Once the cream cheese starts to melt, stir in 1/2 cup fat-free, low-sodium chicken broth. Pour the cream cheese mixture over the pierogies, and sprinkle with 1/2 cup cheddar cheese. Bake the casserole at 400 degrees Fahrenheit for 20 minutes. Remove from the oven, and top with the bacon, 1/4 cup sliced green onions, 1/2 teaspoon freshly ground black pepper and 1/4 cup chopped plum tomatoes.
Another pierogi casserole replaces the pierogies with lasagna noodles and mashed potatoes. Stir together 4 cups hot mashed potatoes, 1/2 cup chive and onion cream cheese spread, 6 minced green onions, 1/2 cup crumbled bacon and 1 cup shredded cheddar cheese. Layer the noodles and potato mixture in a baking dish. Top with bacon and cheddar, cover, and bake at 375 degrees Fahrenheit for 33 to 35 minutes.