Whisk together flour, baking powder, salt, and chai spice in a medium bowl. Set aside.

Cream butter and light brown sugar in the bowl of a stand mixer fitted with the paddle attachment or in a large bowl with a hand mixer (or electric mixer) until a paste forms. Add egg and vanilla extract, and beat well to combine.

Reduce the mixer to low and add dry ingredients in three additions, waiting until almost all the flour has been incorporated before adding the next.

Scoop with a large cookie scoop or roll into balls about 3 tablespoons in size. Chill dough before baking. Bonus points for freezing!

Preheat the oven to 325°F convection (with fan) or 350°F conventional (no fan).

Place dough 2 inches apart on cookie sheet lined with parchment paper and bake in a preheated oven for 15-16 minutes (from frozen, for a 16 cookie yield) until the edges are a nice golden brown, the centers have puffed and the surface looks matte not shiny. Cool completely. You can cool them on a wire rack or on the baking sheet.