Line a 9x13 inch pan with parchment paper, ensuring it covers the bottom and sides.

Spread 2 cups of mini pretzels evenly across the pan to create a base. Preheat your oven to 350°F (175°C).

In a medium saucepan, melt 1 cup of unsalted butter over medium heat. Stir in 1 cup of brown sugar and ¼ teaspoon of salt. Bring the mixture to a boil, then cook for 3–4 minutes without stirring until it turns amber.

Pour the toffee evenly over the pretzels, spreading it with a spatula. Bake for 5 minutes in the preheated oven to set.

While the toffee is baking melt the chocolate chips in the microwave with the vegetable oil until smooth.

Remove the toffee from the oven and pour the melted chocolate all on top, then spread evenly.

Top with 2 cups of red and green M&Ms and the chopped pecans. Finish by sprinkling on the flaky sea salt. Cool at room temperature for 15 minutes, then refrigerate for 10 minutes until firm.

Break into pieces and serve!