Step 1:
Preheat your oven to 350°F (175°C). Line a 9×13-inch baking dish with parchment paper, leaving some overhang on the sides to make removing the bars easier later on.

Step 2:
In a medium saucepan, melt the unsalted butter and unsweetened chocolate over low heat. Stir occasionally until the mixture is completely smooth. Remove the pan from the heat and let it cool slightly before moving on to the next step.

Step 3:
In a large mixing bowl, whisk together the granulated sugar, eggs, and vanilla extract. Once the chocolate mixture has cooled slightly, gradually stir it into the sugar and egg mixture until fully incorporated.

Step 4:
In a separate bowl, whisk together the all-purpose flour, baking powder, and salt. Slowly add the dry ingredients to the chocolate mixture, stirring just until everything is combined and no streaks of flour remain.

Step 5:
Spread the batter evenly into your prepared baking dish, ensuring it reaches all the corners. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Once baked, set the cake base aside and allow it to cool completely.

Step 6:
While the cake is cooling, prepare the gooey caramel topping. In a medium saucepan, combine the sweetened condensed milk, brown sugar, heavy cream, and butter. Cook the mixture over medium heat, stirring constantly to prevent it from burning. After about 10-15 minutes, the mixture should thicken and develop a rich, caramel-like consistency.

Step 7:
Remove the saucepan from heat and stir in the chopped pecans and shredded coconut. Mix until everything is evenly coated with the caramel sauce.

Step 8:
Pour the caramel pecan-coconut mixture over the cooled chocolate base. Use a spatula to spread it out evenly across the surface. Ensure that the topping covers the entire cake base for a uniform gooey layer in every bite.

Step 9:
Allow the bars to set completely at room temperature, or place them in the fridge to speed up the process. Once fully set, lift the bars from the pan using the parchment overhang and cut them into squares.