01 - Preheat oven to 350°F. Line an 8-inch square baking pan with parchment paper, leaving enough overhang on two sides to lift the brownies out later.
02 - Place the butter and chopped dark chocolate in a heatproof bowl set over a saucepan of barely simmering water. Stir gently until completely melted and smooth, then remove from heat.
03 - Whisk the sugar into the melted chocolate mixture until well blended. Beat in the eggs one at a time, mixing thoroughly after each addition. Stir in the vanilla extract.
04 - Gently fold the flour and salt into the batter using a spatula, mixing only until just combined. Avoid overmixing to keep the brownies tender.
05 - Pour the batter into the prepared pan and spread it into an even layer. Bake for 25–30 minutes, or until a toothpick inserted in the center comes out with moist crumbs attached. Do not overbake.
06 - Let the brownies cool completely in the pan set on a wire rack. This ensures a firm base for the toppings.
07 - Spread the thinly sliced strawberries in an even layer across the entire surface of the cooled brownie base.
08 - Melt the semisweet chocolate together with the coconut oil (or butter) in a heatproof bowl over simmering water, stirring until glossy and smooth.
09 - Pour the melted chocolate over the strawberry layer, gently spreading with a spatula to cover the surface evenly.
10 - Refrigerate the pan for at least 1 hour, or until the chocolate coating is fully hardened and set.
11 - Lift the brownies from the pan using the parchment paper overhang. Cut into 12 squares using a sharp knife warmed under hot water and dried, wiping the blade between cuts for clean edges. Serve chilled or at room temperature.