First, make the cake. Preheat oven to 350F and spray two 6" round cake pans with nonstick baking spray.
In a small bowl, whisk together the ground flaxseed with the water and set aside to thicken.
Next, brew the coffee. I use a French press, so I combined ⅔ cup of boiling water with 3 tablespoon of the coffee. Set aside to steep as you make the rest.
In the bowl of a stand mixer, combine the flour, baking powder, baking soda, salt, and sugar.
Add in the vegan butter, and beat on low until it's incorporated and has a sandy texture.
In a small bowl, whisk together the oil, flaxseed mixture, nondairy yogurt, and vanilla extract, and add them to the dry ingredients. Mix until combined.
Pour in the cooled coffee, and beat on medium-low until smooth and creamy.
Divide batter evenly among the 2 pans, and bake for 35-40 minutes until cake is set in the center and a toothpick comes out clean.
When the cakes are completely cooled, you can make the frosting. In the bowl of a stand mixer, beat the shortening, vegan butter, and vanilla extract together until completely smooth and creamy. Add in the powdered sugar, 1 cup at a time, until a thick frosting forms. Add in the salt. It is normal to need to add 1-2 tablespoon of milk to get the right consistency.
To assemble the cake, divide the 2 cake layers in half to create 4 thin layers.
Place one cake piece on your cake stand or platter, and spread some frosting on top. Repeat with all.
Next, cover the cake with the remaining frosting. I always like the "naked" look, so I cover the cake and use a bench scraper to get rid of any excess. Repeat to fill any gaps!
Let the cake chill for 30 min-1 hr before covering with the ganache.
To make the ganache, place about ½ cup of white chocolate chips in a microwave-safe bowl. Add in a splash of nondairy milk, and microwave in 20 second intervals until smooth and creamy. Add more milk and keep stirring if the mixture is too thick.
Transfer your white chocolate ganache to a squeeze bottle, and decorate the cake. Finally, use any extra frosting to decorate the top (or make another half batch). I used a 1M tip and just piped frosting in different heights. Finish off with coffee beans and sprinkles as desired.
Allow the cake to chill until it's time to serve, and store leftovers in the fridge. Enjoy!