1 cup butter, room temperature
8 ounces Parmesan cheese, finely grated
8 ounces sharp Cheddar, finely grated
3/4 teaspoon Dijon mustard
2-1/3 cups all-purpose flour
1/4 teaspoon salt
1 teaspoon baking powder
1/2 teaspoon ground hot red pepper
Preheat oven to 375 degrees.
Cut the butter into thin pieces and beat with an electric hand mixer in a very large mixing bowl until butter is soft. Add all the cheese and beat with the butter until the mixture is smooth. Stir in the mustard.
Whisk together the flour, salt, baking powder, and hot red pepper. Add to the butter mixture and beat until combined. Form into a ball.
Press dough out with a cookie press into straws or divide dough into fourths. On waxed paper, roll each piece into a rectangle 1/3 inch thick. Use a pastry wheel to cut dough into 4- x 1/2-inch strips. Move straws onto a rimmed baking sheet lined with a silicone mat or parchment paper.
Bake at 375 degrees for 8 to 15 minutes, until light brown. Do not overly brown straws. Cool on a rack.