Step 1: Prepare and Preheat
Position your oven rack about 6 inches from the broiler element. Preheat your oven to 400°F (200°C). Line a large baking sheet with aluminum foil or parchment paper for easy cleanup, though this step is optional.

Step 2: Slice the Bread
Using a sharp serrated knife, slice the bread loaf in half horizontally, creating two long halves with flat cut sides facing up. If your loaf is very long, you can cut it in half crosswise first to create four pieces that fit better on your baking sheet. Place the bread cut-side up on the prepared baking sheet.

Step 3: Make the Garlic Butter
In a small mixing bowl, combine the softened butter, minced garlic, parsley, Italian seasoning, salt, pepper, and red pepper flakes (if using). If using olive oil, add it now. Mix everything together with a fork or spoon until well combined and the garlic is evenly distributed throughout the butter. The mixture should be smooth and spreadable.

Step 4: Spread the Garlic Butter
Using a butter knife or offset spatula, generously spread the garlic butter mixture evenly across the cut surface of each bread half. Make sure to spread it all the way to the edges so every bite is flavorful. Don’t be shy with the garlic butter – this is what makes the toast so delicious! Press the butter into the bread slightly so it soaks in.

Step 5: First Bake
Place the baking sheet in the preheated oven and bake for 5-6 minutes, just until the bread starts to turn golden around the edges and the butter is melted and bubbling. You’re not looking for it to be fully toasted yet – just lightly golden.

Step 6: Add the Cheese
Remove the baking sheet from the oven. Sprinkle the shredded mozzarella cheese evenly over both bread halves, covering the entire surface. Then sprinkle the Parmesan cheese over the mozzarella. The cheese layer should be generous – don’t hold back!

Step 7: Broil Until Golden
Switch your oven to the broiler setting (high heat). Return the baking sheet to the oven and broil for 1-3 minutes, watching very carefully. The cheese should melt completely and turn golden brown with some beautifully browned spots. Keep a close eye on it as broilers work quickly and you don’t want it to burn. The exact time will depend on your broiler’s intensity.

Step 8: Slice and Serve
Remove the cheesy garlic toast from the oven immediately. Let it cool for just 1-2 minutes, then use a sharp knife to cut each half into individual serving pieces (typically 2-3 inch slices). Serve immediately while hot, gooey, and at its absolute best!