In a mixing bowl, combine softened butter, fresh basil pesto, and finely grated Parmesan cheese. If desired, add minced garlic. Mix until thoroughly blended and smooth.

Lay down plastic wrap on a clean surface. Spoon the mixture onto the wrap and shape into a rough log, rolling it neatly.

Twist the ends of the plastic wrap tightly to secure the butter log. Tie one end with a knot.

Refrigerate the wrapped log for 1-2 hours, or freeze for 45-60 minutes until firm.

Remove from wrap and slice into disks about 1/2 inch thick. Store slices in an airtight container in the fridge for up to 3 days or freeze for 3 months.