Prep your pan. Line a small rimmed baking sheet (quarter sheet) or an 8x8-inch pan with parchment.
Let the paper overhang for easy lifting.
Melt the chocolate. In a microwave-safe bowl, combine the chocolate and 1 tablespoon coconut oil. Microwave in 20–30 second bursts, stirring between each, until smooth. Alternatively, melt in a double boiler over gentle heat.
Sweeten if needed. If using unsweetened chocolate, whisk in powdered erythritol or allulose to taste.
Stir well so it dissolves. Add vanilla if using.
Warm the peanut butter. In a separate bowl, microwave the peanut butter for 10–15 seconds to loosen. If it’s very thick, stir in 1 teaspoon coconut oil so it drizzles easily.
Spread the base. Pour the melted chocolate onto the lined pan and spread into an even layer about 1/8–1/4 inch thick.
Add the peanut butter. Drizzle warm peanut butter over the chocolate in thin ribbons.
Use a toothpick or knife to create swirls. Don’t overmix—you want distinct streaks.
Top it off. Sprinkle with flaky sea salt and any add-ins like chopped nuts or cacao nibs. Press gently so they adhere.
Set in the freezer. Freeze for 15–25 minutes, until firm and snappy.
Break into pieces. Lift the bark by the parchment and snap into shards.
Aim for 16–20 pieces for easy portioning.
Store properly. Keep the bark in an airtight container in the fridge or freezer. See storage tips below.