In a medium bowl, whisk together the flour, baking soda, ground cinnamon, and salt. Set aside.
1 ½ (188 g) cup All purpose flour, 1 teaspoon Ground cinnamon, ¾ teaspoon Baking soda, ¾ teaspoon Kosher salt
In the bowl of a stand mixer fitted with the paddle attachment (alternatively you can do this in a large bowl with an electric mixer), beat butter and Biscoff spread on medium high speed until smooth and fully combined, about 2 minutes.
½ (113 g) cup Unsalted butter, ½ (128 g) cup Lotus Biscoff Spread or Trader Joe's Speculoos Spread
Add in the light brown sugar and granulated sugar and beat on medium high speed until light and fluffy, about 2 minutes.
½ (110 g) cup Light brown sugar, ¼ (50 g) cup Granulated sugar
Beat in the egg and vanilla extract and mix until combined, scraping the sides and the bottom of the bowl making sure everything is fully incorporated.
1 large Egg, 1 tablespoon Vanilla extract
Add all of the flour mixture and mix on low speed until almost combined (do not mix flour until it is fully combined, you should still see some streaks of flour) . Remove the bowl from the stand mixer and add in the semisweet chocolate chips. Using a rubber spatula, gently fold in the chocolate chips while also incorporating the last bit of flour. Mix until just combined, being careful not to over-mix the dough.
1 ½ cup Semisweet chocolate chips
Using a cookie scoop, scoop the dough to form 2 ½ tablespoon sized dough balls. If you have a kitchen scale, each ball of dough should be 1.7 ounces. (You dont have to worry about rolling the dough into perfect balls after scooping. You'll do that right before you bake them). Place cookie dough balls on a plate lined with wax paper. Cover the dough balls with plastic wrap and chill in the refrigerator for 45 minutes.
After 45 minutes, preheat the oven to 350 F and line a large baking sheet with parchment paper, set aside. In a small bowl, combine ¼ cup of granulated sugar and ground cinnamon and stir until combined. Remove the cookie dough from the refrigerator and roll into smooth balls. Lightly roll the dough in the cinnamon sugar.
¼ (50g) cup Granulated sugar, ¾ teaspoon Ground cinnamon
Place 6 dough balls on the prepared baking sheet. Bake for 10 to 12 minutes. The cookies are ready when they have puffed up, the middle of the cookies look soft and slightly underbaked, and the edges are lightly golden brown and set.
Remove the cookies from the oven and firmly slam the baking sheet on a heatproof surface to deflate the cookies. Top cookies with extra chocolate chips. Allow cookies to cool on the baking sheet for 10 minutes then transfer to a cooling rack to cool completely.