1/2 cup (1 stick) butter
1 cup brown sugar, packed
1 teaspoon cinnamon
1 pound walnut halves or large pieces (about 4 cups)
In the microwave, melt butter in a 1-1/2 qt. casserole dish (30 seconds to 1 minute at high).
Stir in brown sugar and cinnamon. Microwave at high 2 minutes. Mix well to combine butter and sugar.
Add nuts and mix to coat. Microwave at high 3 to 5 minutes.
Spread out onto wax paper and cool slightly. Serve warm or cold.