Preheat oven to 350F and line a 9x9 pan with parchment paper.
Whisk together the melted butter, melted chocolate, powdered allulose, eggs, and vanilla until glossy. Fold in almond flour, cocoa powder, and salt.
Spread into the pan and bake for 24 to 27 minutes until just set with a fudgy center. Cool completely.
Combine heavy cream, brown allulose, butter, and egg yolks in a saucepan. Cook over medium-low heat, whisking constantly, for 6 to 8 minutes until thickened.
Remove from heat and stir in vanilla extract, then fold in the shredded coconut, chopped pecans, and a pinch of salt.
Let the topping cool for 15 minutes until thick and spreadable but still slightly warm.
Spread generously over the cooled brownies, creating texture peaks with the coconut and pecans for that signature German chocolate look.
Chill 30 minutes to set, then slice into thick squares revealing the rich layers.