Line a baking sheet with parchment paper. Toast the pecan halves in a dry skillet over medium heat for 3 to 4 minutes until fragrant, stirring often. Set aside.
In a small saucepan over medium heat, melt the butter. Add the brown sugar erythritol, heavy cream, and sea salt. Stir constantly and bring to a simmer. Cook for 3 to 4 minutes until the caramel thickens and darkens slightly. Remove from heat and stir in the vanilla extract.
Arrange small clusters of 4 to 5 toasted pecan halves on the parchment-lined baking sheet. Spoon the warm caramel over each cluster, letting it drip down and hold the pecans together.
Let the clusters cool for 15 minutes until the caramel sets.
Melt the sugar-free dark chocolate chips with coconut oil in the microwave in 30-second bursts until smooth. Drizzle the chocolate over each cluster using a fork or spoon.
Sprinkle with flaky sea salt and refrigerate for 20 minutes until the chocolate is firm. Store in the refrigerator.
