Step 1

Heat a cast iron skillet over medium heat.

Step 2

Add walnuts and toast until beginning to brown (about 5 minutes), stirring frequently.

Step 3

Pour pure maple syrup over the walnuts in the pan.

Step 4

Bring to a boil, stirring constantly.

Step 5

Cook until thick, about 30 seconds.

Step 6

Remove from heat. Topping may be served over cake or ice cream either warm or cooled.