1. Preheat oven to 300°.
2. Beat egg white with a mixer at medium speed in a medium bowl until foamy. Combine sugar and next 3 ingredients. Add sugar mixture to beaten egg white, 1 tablespoon at a time, beating until stiff peaks form. Fold in cereal and next 3 ingredients. Spread cereal mixture on a foil-lined baking sheet coated with cooking spray.
3. Bake at 300° for 20 minutes, stirring after 10 minutes. Cool completely in pan on a wire rack. Store in an airtight container.
This is a versatile snack mix, so feel free to substitute another type of nut in place of the pecans (almonds would be delicious), or try dried cranberries or raisins in place of the cherries.