Prep the pan: Line a rimmed baking sheet or a 9x13-inch pan with parchment paper. Make sure it overhangs the edges for easy lifting.
Toast the pecans: Place pecans in a dry skillet over medium heat for 4–6 minutes, stirring often, until fragrant and slightly darker. Let cool.
Melt the chocolate: In a microwave-safe bowl, heat chocolate in 20–30 second bursts, stirring between each.
Stop when it’s mostly melted and smooth. Stir in a teaspoon of oil if using.
Spread the chocolate base: Pour about two-thirds of the melted chocolate onto the lined pan. Spread into an even layer about 1/4-inch thick.
Make the caramel: In a small saucepan, melt caramels with heavy cream over low heat, stirring constantly until smooth.
Stir in butter and vanilla if using.
Add pecans: Sprinkle toasted pecans evenly over the chocolate layer. Press lightly so they adhere.
Layer the caramel: Drizzle the warm caramel over the pecans. Aim for thin ribbons rather than one thick slab, so it’s easier to bite.
Top with remaining chocolate: Spoon the rest of the melted chocolate over the caramel in streaks.
Use a spatula to gently swirl and cover, leaving some caramel peeking through.
Finish with sea salt: Sprinkle flaky sea salt over the top. This balances sweetness and adds a little crunch.
Set and chill: Refrigerate for 30–45 minutes, until firm. Avoid freezing, which can cause condensation later.
Break into pieces: Lift the bark out with the parchment and break into rustic shards.
If you prefer neat squares, cut with a warm knife.