Potato-Cheddar Pierogi

1. Put the potatoes in a medium pot and cover with cold water. Bring to a boil and cook until fork tender, 20 to 30 minutes. Drain the potatoes and let rest until the skins are dry. Transfer the potatoes to a mixing bowl.
2. Mash the potatoes until just broken up. Add the smoked paprika, garlic powder, onion powder, 1 tablespoon salt and 1/2 tablespoon pepper. Continue mashing until there are no lumps and the dry ingredients are thoroughly mixed in. Add the cream cheese and continue mixing until blended. Add the Cheddar; mix until blended (see Cook's Note). Refrigerate until chilled.
3. To assemble the pierogi: On a well-floured surface, roll out a ball of Pierogi Dough the size of a large orange into a rectangle about 1/8-inch thick. Cut out 3-inch rounds of dough (a pint glass will do).
4. Place 2 tablespoons of filling in the center of each round, then fold the rounds in half. Take care to make sure all the air pockets are pressed out of the pierogi. Crimp the edges with a fork or your fingers.
5. Boil the pierogi for 3 minutes, then brown in a skillet. Serve with caramelized onions and sour cream.

Pierogi Dough:

1. Add the eggs, flour, mashed potatoes, baking powder, salt and 1/2 cup water to the bowl of a stand mixer fitted with the dough hook attachment. Mix until the dough is smooth and elastic, about 5 minutes.
2. Cover the dough in plastic wrap or a slightly damp cloth. Let rest in the refrigerator for at least 15 minutes and up to 4 hours.