Preheat oven to 350°F. Line a baking sheet with parchment paper or a silicone baking mat.

Mix dry ingredients:

In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.

Cream butter and sugars:

In a large bowl, use a hand mixer or stand mixer to cream the softened butter, peanut butter, brown sugar, and granulated sugar until light and fluffy—about 2–3 minutes.

Add wet ingredients:

Mix in the maple extract, egg, and milk until fully combined.

Combine wet and dry:

Slowly add the dry ingredients to the wet mixture and mix until just combined (don’t overmix).

Fold in the mix-ins:

Gently stir in the chocolate chips and broken Biscoff cookie pieces with a spatula or wooden spoon.

Scoop and bake:

Use a cookie scoop or tablespoon to drop dough onto the prepared baking sheet, spacing them about 2 inches apart.

Bake for 10–12 minutes, or until the edges are lightly golden and the centers are just set. Don't overbake—they'll continue to cook on the baking sheet after you take them out.

Cool:

Let cookies rest on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.

Tips:

If you like extra crunch, sprinkle a few more crushed Biscoff pieces on top before baking.

Want extra gooeyness? Press a few chocolate chips into the tops right after baking.