Preheat the oven to 375°F. Spray a 12-cup muffin tin with nonstick cooking spray or line the cups with paper liners.
In a large mixing bowl, use an electric mixer to combine the peanut butter, egg, granulated sugar, brown sugar, and milk. Beat the ingredients until smooth.
Add the flour and baking powder. Mix until just blended. Do not overmix.
Stir in the peanut butter chips with a wooden spoon.
Pour the batter into the prepared muffin tin so each cup is about two-thirds full.
Bake for 18–20 minutes or until the muffins are light brown on top. Using pot holders, remove the muffin tin from the oven and place it on a cooling rack. Cool 5 minutes in the muffin tin, then carefully turn the tin over to remove the muffins.
Serve warm or let the muffins cool before eating.
For a different twist, you can substitute ¼ cup chocolate chips for ¼ cup of the peanut butter chips.
Excerpted from The Everything Kids’ Cookbook, Updated Edition by Sandra K. Nissenberg. Copyright © 2002, 2008, 2020 by Simon & Schuster, Inc. Photographs by Kelly Jaggers. Used with permission of the publisher, Adams Media, an imprint of Simon & Schuster. All rights reserved.