In a bowl, whisk together the dry ingredients. Add in wet ingredients and chocolate chips and stir until just combined.
In a separate bowl stir together the ingredients for the peanut butter filling, adding more milk if necessary to reach a peanut butter consistency.
In two prepared muffin tins drop large spoonfuls of chocolate batter into each, enough to cover the bottom of the tin. Then place ½ of the peanut butter filling in the middle of each and then top with remaining chocolate batter and a few more chocolate chips.
Bake at 350 °F for 10-12 minutes, until set and a toothpick inserted into the center comes out clean.
Notes
These are the perfect treat when you just need something small!