Line a baking sheet with foil and spray foil with coconut oil baking spray. Sprinkle nuts across sheet pan and set aside.
In a small saucepan over medium-low heat, melt butter, heavy cream, Truvia, sea salt, and vanilla extract. Bring to a boil and let bubble for 6 minutes, stirring occasionally, until caramel is deep golden brown.
Pour caramel over nuts and quickly gather stray nuts from around the edges to the caramel – it will set up almost immediately. Sprinkle chocolate chips overtop and place sheet pan under broiler on high for 1-2 minutes, or until chocolate chips are melted (be sure to watch it closely!).
Spread melted chocolate chips across top of toffee with a spatula. Place toffee in refrigerator until it solidifies, 30-60 minutes. Break into chunks and store in an airtight container in refrigerator for up to two weeks.