Using 1/3 cup of the Biscoff cookie butter, scoop 1/2 tsp sized balls and place on small cookie sheet. Put in freezer for 30 minutes to an hour to get very firm so that they are easier to work with.
To make the cookie dough, in electric stand mixer, cream together butter, 1/2 cup granulated sugar and brown sugar. Once light and fluffy (about 3 minutes), add remaining 1/2 cup Biscoff cookie butter and mix until combined. Add eggs one at a time, mixing well between each addition. Mix in vanilla extract.
In a seperate bowl, sift together flour, salt, baking soda and cinnamon. Add to butter mixture and mix together until just combined, taking care not to overmix the dough. Using a small cookie scoop, scoop your cookie dough into balls and place all together on a baking sheet. Cover with plastic wrap and place in refrigerator for at least 30 minutes, or until the dough is nice and firm.
When filling the cookie dough ball, make a little nest in the dough, insert the cookie butter center and gently fold up the dough to fully incase the cookie butter. Gently roll it into a smooth ball and finish it off by rolling it in the reserved 1/2 cup granulated sugar.
Preheat oven to 350°. Place cookie dough balls 2 inches apart on baking tray that has been lined with parchment paper or a silpat. Very gently press down on each dough ball with the palm of your hand just to very slightly level out the tops.
Bake cookies for 12-13 minutes or until tops are slightly golden brown. Allow to cool on baking sheet for about 5 minutes then place cookies to cool completely on a wire rack.