Beat the butter with an electric mixer at medium speed for one minute. Add the sugars and beat until fluffy and well blended, about 2 minutes. Add the Biscoff Spread, salt and vanilla and mix at medium-low speed until blended, scraping down the sides of the bowl as necessary. Add the flour and mix until just combined. Turn the dough out onto a work surface, divide in half, and shape into two discs. Wrap each disc in plastic wrap and refrigerate until chilled, at least 2 hours (or up to 3 days.)

Preheat the oven to 350˚F. Line two baking sheets with parchment paper.

Place one of the chilled dough discs on a lightly floured work surface. Using a rolling pin, roll the dough out to a thickness of ½ inch. Using a 2-inch round or fluted cookie cutter, cut out as many cookies as possible from the dough. Arrange on one of the prepared cookie sheets, spacing them ¾ inch apart. Gather up the scraps, rewrap them, and chill for about 15 minutes before rerolling and cutting more cookies.

Bake for 24 to 28 minutes, until they are just firm and slightly browned. Cool the cookies on the baking sheet for 10 minutes, then transfer them carefully to a wire rack and cool completely. Repeat the rolling, cutting and baking procedure with the remaining dough.