Prepare the Whipped Feta: In a bowl, blend the crumbled feta and cream cheese using a hand mixer until smooth and creamy. Set aside.
Make Garlic Butter: In a small bowl, mix softened butter and minced garlic until well combined.
Form the Burger Patties: Take the ground beef and season with salt and pepper. Form into large meatballs (about 4 oz each), then lightly flatten them.
Sear the Burgers: Preheat a skillet or grill over medium-high heat. Add the burger patties and smash them down using a spatula. Cook for 3-4 minutes until the edges are crispy.
Add Garlic Butter: In the last minute of cooking, spoon the garlic butter over the patties as they finish cooking.
Assemble: On a toasted bun, add a layer of whipped feta, place your smashed burger on top, and pile on your favorite toppings. Voila!