Prep the pan: Preheat your oven to 350°F (175°C). Line a 9x13 inch baking pan with parchment paper, leaving an overhang on two sides so you can easily lift the bars out later. Lightly grease the paper or spray with non-stick cooking spray.
Mix the base: In a large bowl, use an electric mixer to beat the softened butter and brown sugar together until the mixture is creamy and smooth, about 2–3 minutes. Add the egg and vanilla extract, beating well until fully incorporated and pale in color.
Add coconut: Gently fold in 1 cup of the shredded coconut and the salt using a spatula. Spread this dough evenly into the prepared pan, pressing down gently with wet hands or the back of a spoon to create an even layer about 3/4 inch thick.
Bake until set: Bake for 20–25 minutes. Look closely at your bars: they are done when the edges are just starting to turn golden brown and look set, but the center still looks slightly soft. Do not overbake, or they will become too dry.
Cool completely: Remove from the oven and let the bars cool completely in the pan on a wire rack. This is crucial! The coconut layer needs to firm up before you add the chocolate topping.
Melt the chocolate: In a medium microwave-safe bowl, combine the chocolate chips, butter, and heavy cream. Microwave in 30-second intervals, stirring well after each burst, until the mixture is smooth and glossy. If making it on the stove, melt over low heat while stirring constantly.
Top and finish: Once the bars are completely cool to the touch, pour the melted chocolate evenly over the top. Sprinkle with a pinch of sea salt right away so it sticks. Let these sit at room temperature until the chocolate has fully hardened, about 1–2 hours.
Cut and serve: Use the parchment paper overhang to lift the slab out of the pan onto a cutting board. Cut into squares (usually 9 bars) and enjoy!