Step 1: Bring a large pot of salted water to a boil and cook the pasta according to package directions until al dente. Reserve 1 cup of pasta water before draining.
Step 2: In a small skillet, melt 2 tablespoons of butter over medium heat. Add the breadcrumbs and toast, stirring constantly, until golden brown and fragrant. Remove from heat and set aside.
Step 3: In a large skillet, heat the remaining butter and olive oil over medium-low heat. Add the minced garlic and red pepper flakes, sautéing for 2-3 minutes until soft and fragrant but not browned.
Step 4: Add the drained pasta to the garlic butter mixture. Pour in 1/2 cup of the reserved pasta water and toss vigorously to create a silky sauce.
Step 5: Stir in the fresh parsley and half of the Parmesan cheese. If the pasta seems dry, add more pasta water a tablespoon at a time.
Step 6: Plate the pasta and top generously with the toasted buttery breadcrumbs and the remaining Parmesan cheese. Serve immediately.