01 -
Beat the butter in a mixing bowl until smooth, about 1 minute. Add the cheddar and parmesan and mix until evenly combined.
02 -
Add flour, cornstarch, salt, pepper, and smoked paprika. Mix on low just until crumbly, then fold in the minced jalapeño until the dough holds together when pressed.
03 -
Divide the dough in half. Roll each half into a log about 1 1/2 inches wide, wrap tightly in plastic wrap, and chill for at least 1 hour until firm.
04 -
Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
05 -
Cut the chilled logs into 1/4-inch thick slices. Arrange on the prepared baking sheets about 1 inch apart.
06 -
Bake for 15-18 minutes, until the edges are lightly golden and the centers look set. Cool on the pan for 5 minutes, then transfer to a wire rack to cool completely.