Begin by bringing a large pot of salted water to a rolling boil over high heat. Once bubbling vigorously, add your choice of pasta, cooking according to package instructions until al dente, usually around 8-10 minutes.

In a medium saucepan, melt 2 tablespoons of butter over medium heat, stirring often until it's completely melted, about 1-2 minutes.

Sprinkle in 2 tablespoons of flour and whisk continuously for another 2 minutes until the mixture is bubbly and slightly golden.

Gradually pour in 1 cup of milk while whisking constantly to prevent lumps and cook until thickened, about 3-4 minutes.

Reduce heat to low and stir in ½ to ¾ cup of pesto, mixing until well combined.

Drain the cooked pasta using a colander and return to the pot. Pour the creamy pesto sauce over the pasta, tossing until thoroughly coated.

Serve and enjoy your creamy pesto pasta with optional toppings such as grilled chicken or sautéed spinach.