Heat sugar in a skillet over medium heat until melted, shaking pan occasionally. Reduce heat to low; cook until golden, stirring as necessary. Stir in oatmeal. Pour onto a baking sheet that's been lined with a silpat or has been buttered. Allow brittle to cool in the refrigerator. Crush hardened oat crunch in a food processor or place candy in a plastic bag and crush with a mallet. Excess crunch should be stored in the 'fridge as it will absorb moisture from the air and become a large lump if left out. Crunch can be used to sprinkle over store-bought ice cream or in granola to make it sweeter.