Add ¼ cup softened unsalted butter, 2 Tablespoons olive oil, 1 teaspoon garlic powder, ½ teaspoon minced fresh parsley, ¼ teaspoon kosher salt, and 1 pinch freshly ground black pepper to a medium bowl. Stir the mixture together until evenly mixed (alternatively, you can mix it together with a mini food processor).
Garlic Bread Grilled Cheese
Heat a medium- to large (depending on how many sandwiches you want to cook at once) skillet over medium heat while you assemble the sandwich(es).
For each sandwich you want to make, lay out 2 slices thick-cut white bread on a cutting board. Spread about 1 teaspoon of the garlic butter spread onto one side of each slice of bread.
Flip one of the slices of bread over so that the non-buttered side is facing up. Add 1 slice provolone cheese and ¼ cup shredded mozzarella to the bread. Top with the other slice of bread, with the buttered side facing up.
Carefully transfer the sandwich to the skillet. Cover the skillet and cook until the bottom slice of bread is golden brown (about 5 minutes). Flip the sandwich, keeping the skillet uncovered while the other side toasts. Cook until the second slice of bread is golden brown and the cheese is melted, about 3-5 more minutes. Cut the sandwich in half and serve immediately.
Store any leftover garlic butter spread in an airtight container in the fridge. Use it to make more garlic bread grilled cheese, or just regular garlic bread.