01 -
Beat the softened butter, cream cheese, and granulated sugar in a large bowl on medium speed for about 2 minutes, until smooth, pale, and creamy. Scrape down the bowl.
02 -
Mix in the egg yolk and vanilla until fully blended. Scrape the bottom of the bowl so the dough mixes evenly.
03 -
In a separate bowl, whisk together the flour, cornstarch, baking powder, cinnamon, and salt. Add to the butter mixture and mix on low just until no dry flour remains.
04 -
Cover the bowl and refrigerate for 45 minutes, or until the dough is firm enough to scoop and roll without sticking badly.
05 -
Heat the oven to 350°F (175°C). Line two baking sheets with parchment paper. Stir the coating sugar and cinnamon in a small bowl. Scoop 1 tablespoon portions of dough, roll into balls, and coat well in cinnamon sugar.
06 -
Place dough balls 2 inches apart on the baking sheets. Bake for 10-12 minutes, until the edges are set and the tops look dry but pale. Cool on the pan for 5 minutes, then transfer to a wire rack.