Preheat the oven to 300 degrees F (150 degrees C).

Combine flour, salt, and red pepper flakes in a large bowl; add Cheddar cheese and toss until cheese is coated. Pour in melted butter; stir until mixture is moist and crumbly. Add rice cereal and knead by hand until dough is well-blended.

Roll dough into 1/2-inch balls; arrange on a baking sheet. Flatten each ball with a fork.

Bake in the preheated oven until light and crispy, about 30 minutes.