Preheat the oven to 350°F/180°C. Line two 8-inch springform round pans with parchment paper. Grease the sides.
Make the Keto Cake Layers. In a large mixing bowl, add the eggs, melted butter, almond milk, and vanilla extract. Use an electric mixer to beat until frothy for about 2 minutes.
Add the coconut flour, sweetener, cocoa powder, baking powder, and a pinch of salt to the egg mixture. Mix well until the batter is smooth and creamy.
Divide the batter between the prepared cake pans. Bake for 20 minutes until firm to touch. Remove from the oven and allow to cool completely.
Make the German Chocolate Cake Frosting. Place a saucepan over medium heat and add heavy cream, brown sweetener replacement, egg yolks, and butter. Bring the mixture to a gentle boil, occasionally stirring until the butter is melted.
Sprinkle the xanthan gum, and whisk to combine. Reduce to low heat, and continue to simmer for about 5 minutes, or until the liquid starts to thicken. Remove from heat and mix in unsweetened shredded coconut, vanilla, and toasted chopped pecans.
Let the filling cool completely before assembling the cake. The mixture will cool even more as it cools.
Assemble the cake. Place the first layer on a cake stand or plate. Top with half of the cake filling and spread it evenly.
Repeat the process with the second cake layer and top with the remaining coconut pecan filling.
Decorate with coconut flakes and toasted pecans. Refrigerate for at least 2 hours before serving, preferably overnight.