In a stand mixer fitted with a paddle attachment, combine the flour, sugar, baking powder and salt.

Add the peanut butter to the dry ingredients and blend until the peanut butter is fully combined into the flour and has a crumbly texture.

In a separate bowl, whisk together the whole milk, eggs and vegetable oil. Slowly pour the wet ingredients into the mixer with the dry ingredients, allowing the batter to fully blend. The key here is to really add the wet ingredients slowly to prevent lumps from forming.

Line a muffin tray with paper muffin liners or grease the tray with butter or cooking spray. Scoop the muffin batter into the muffin cups, filling them about 3/4 of the way full.

Bake the muffins for 20 minutes in a 350 ̊F oven. Remove from the oven and allow the muffins to cool then serve immediately or store at room temperature for up to a week.