Preheat oven to 275 degrees F (135 degrees C). Spray a large roasting pan with non-stick cooking spray.
In a medium-size microwave safe bowl, mix butter, white corn syrup and brown sugar. Place the mixture in the microwave and cook 2 minutes, or until butter melts.
Place the cereal, pecans and almonds into the prepared roasting pan. Pour the melted butter mixture over the cereal and nuts and mix gently until the cereal and nuts are coated.
Bake for 1 hour, stirring every 15 minutes.
As the snack mix is cooling, be sure to continue to stir so that the mix will not harden in one big lump.
