Allow the butter to soften at room temperature.
In a mixing bowl, combine the butter with basil pesto, grated Parmesan cheese, minced garlic, lemon zest, black pepper, and salt.
Mix until smooth and evenly blended.
Shape the butter into a log using parchment paper or transfer it to an airtight container.
Refrigerate for at least 1 hour until firm.
Slice or melt over pasta, grilled meats, vegetables, potatoes, or fresh bread before serving.