Preheat your oven to 350°F (175°C).
Line a baking sheet with parchment paper and spread the pretzel twists evenly on the prepared baking sheet.
In a medium saucepan, melt the butter over medium heat. Stir in the brown sugar and bring to a gentle boil, stirring constantly for about 3-4 minutes until it thickens slightly.
Remove from heat and stir in the vanilla extract. Pour the butter toffee mixture evenly over the pretzels.
Bake for 10-12 minutes until bubbly and golden.
Remove from the oven and immediately sprinkle chocolate chips over the top. Let sit for a few minutes to soften, then spread the melted chocolate evenly over the pretzels. If using nuts, sprinkle them on top along with a pinch of sea salt. Allow to cool completely before breaking into pieces.