½ teaspoon coarse sea salt, or to taste (Optional)
Instructions
Butter a 10x15-inch baking sheet or line with parchment paper.
Spray a heatproof spoon with cooking spray. Stir sugar and corn syrup together in a 2-quart microwave-safe bowl using the greased spoon. Microwave on high until very bubbly, 2 1/2 to 4 minutes.
Quickly stir in nuts and butter. Continue microwaving until bubbles begin to take on a light caramel color, another 2 1/2 to 4 minutes. Watch carefully to make sure the nuts don't burn. Add vanilla extract and baking soda, stirring quickly until bubbly and combined.
Immediately pour mixture onto the prepared sheet pan in a thin layer. Sprinkle with sea salt. Allow to cool and set before breaking into pieces, 30 to 40 minutes.