Melt butter in a large saucepan; stir in cumin and red pepper, and cook 1 minute. Remove from heat; add pecans, sugar, and salt, stirring to coat.
Spread pecans in a single layer in 2 (15- x 10-inch) jellyroll pans. Bake at 300° for 20 minutes, stirring occasionally. Cool and store in an airtight container. Makes 8 cups.