Step 1

To brown the butter, in a medium skillet, melt the butter over medium heat, stirring occasionally. The butter will start to foam, and browned specks will begin to form at the bottom of the pan. The butter should have a nutty aroma. Watch the butter carefully because it can go from brown to burnt quickly. Pour the brown butter into a bowl and let it cool to room temperature.

Step 2

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

Step 3

In the bowl of a stand mixer or with a hand mixer, mix the brown butter, brown sugar, and sugar together until combined. Add the Biscoff spread and mix until smooth. Add the eggs and vanilla extract and mix until combined.

Step 4

Add the dry ingredients and mix on low until just combined. Don’t over mix.

Step 5

Form the dough into a large ball and wrap with plastic wrap. Chill in the refrigerator for at least 30 minutes (can chill for 48 hours).

Step 6

When ready to bake, take the dough out of the fridge and preheat the oven to 350 degrees F. Line a large baking sheet with a Silpat baking mat or parchment paper.

Step 7

Form the cookie dough into balls, about 2 tablespoons of dough per cookie. Cut open the dough balls or tear apart with your fingers, making sure you have two even halves. Press down on one side of the dough ball with your finger to make a little hole. Place about 1 teaspoon of Biscoff spread in the center. Don’t add any more than a teaspoon.

Step 8

Place the other half of the dough ball on top of the Biscoff spread and roll into a ball again. Make sure all of the Biscoff spread is covered with dough.

Step 9

In a small bowl, combine the sugar and cinnamon. Roll all of the filled dough balls in the cinnamon sugar mixture until well coated. Place on the prepared baking sheet, about 2 inches apart

Step 10

Bake for 8 to 11 minutes or until the cookies are slightly set around the edges and barely starting to crackle. The middles should still be soft. Remove from the oven and let the cookies cool on the baking sheet for 5 minutes. Transfer the cookies to a wire cooling rack and cool completely.