First prepare the chocolate cake cookies - Preheat the oven to 350℉
In a large mixing bowl combine the cocoa powder with the melted vegan butter, hot coffee, & the vanilla extract whisk smooth. Add the plant milk
Sift the flour, sugar, baking powder & salt directly into the chocolate mixture in the bowl & mix smooth
The batter will be very stiff at first but as you mix by hand with a spatula it will turn to a glossy dough
Scoop with a 2 ounce scoop onto a parchment lined sheet pan spaced 2" apart then bake for 15 minutes or lightly browning on the edges & not raw inside
Cool while you prepare the ganache recipe according to the instructions on that post
Make the buttercream by creaming the vegan butter to smooth, add the confectioners sugar & whip smooth then add 3 Tbs of the cooled ganache to make chocolate buttercream
Make the German Chocolate Filling by melting the vegan butter with the sugar in a medium sauce pot over high heat stirring often. Once the sugar dissolves continue cooking until the mixture starts to turn light amber in color as the sugar caramelizes
Slowly & carefully pour in the room temperature plant milk. After the intense bubbling subsides whisk smooth
Combine the cornstarch with the water & whisk to a slurry then add this to the pot & whisk until it all comes back to a full boil. Boil for just 5 seconds
Remove from heat & add the lightly toasted pecans, coconut flakes & vanilla
Cool completely then ice the cookies with chocolate buttercream & top with German filling. Use the reserved 1 Tbs ganache for a drizzle on top if desired