Preheat the oven to 350 degrees F.

Toast and chop the pecans: Spread the pecans out on a baking sheet and bake for 5-10 minutes, stirring once, until they are fragrant and toasted. Alternatively, heat them in a skillet until fragrant, about 5 minutes. Once cooled, roughly chop the pecans and set aside.

Line a baking sheet with parchment paper or a silpat liner and set aside.

Microwave the caramel: Place the butter in a large microwave-safe bowl and heat until melted. Add brown sugar, granulated sugar, sweetened condensed milk, and corn syrup, stirring well to combine. Return the bowl to the microwave and cook on HIGH power for 6-8 minutes, or until it reaches about 235 degrees.

Carefully remove the bowl from the microwave using hot pads. Stir the vanilla into the hot caramel and mix in the chopped pecans.

Drop large spoonfuls of the mixture onto the parchment-lined baking sheet. Refrigerate until set, about 20 minutes.

Melt the almond bark or chocolate in the microwave, stirring every 30 seconds until smooth.

Submerge a pecan cluster in the melted chocolate using a fork to coat it completely. Lift the cluster out with the fork and place it on the parchment paper to set.

Store the turtles in an airtight container at room temperature or in the refrigerator for 2-3 weeks.