Line a large baking sheet with parchment paper or a silicone baking mat.

In a medium heavy-bottomed saucepan over medium-low heat, combine the sugar, ½ cup of the heavy cream, corn syrup, butter and salt. Let the ingredients melt together slowly, stirring occasionally, until the mixture is completely smooth and the butter is fully melted.

Once smooth, slightly increase the heat to bring the mixture to a gentle simmer. Clip a digital thermometer to the side of the saucepan, making sure the tip is fully submerged but not touching the bottom. Do not stir anymore. Let the caramel simmer over medium-low heat without stirring until it reaches 236°F.

Carefully pour in the remaining ½ cup of heavy cream—again, no stirring! Let the mixture continue cooking until the temperature reaches 245-248°F. Remove from heat and stir in the vanilla.

While the caramel cools, place the chocolate chips and coconut oil in a large microwave-safe bowl. Microwave on 50% power for 20-second increments, stirring after each increment until completely melted and smooth.

Pour about ⅔ of the melted chocolate onto the prepared pan and spread it into an even layer. Scatter the pretzels over the top, pressing them gently into the chocolate. It’s okay if they overlap slightly!

Pour the caramel evenly over the pretzels, making sure it touches as many of them as possible—this is what holds the bark together.

Drizzle the remaining melted chocolate over the top. You can use a spoon or transfer the chocolate to a small plastic bag, snip off a corner and pipe it on for a more controlled drizzle. Sprinkle with flaky salt.