Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans and set them aside.
In a large bowl or the bowl of a stand mixer fitted with the whisk attachment, combine the sugar, all-purpose flour, unsweetened cocoa, Dutch-process cocoa (if using), baking soda, baking powder, and kosher salt; mix on low until evenly combined.
Add the eggs, buttermilk, strong black coffee, vegetable oil, and vanilla extract to the dry ingredients. Beat on medium speed for about 2 minutes; the batter will be thin.
Pour the batter evenly into the prepared pans and smooth the tops.
Bake for 30–35 minutes, or until a toothpick inserted into the center comes out clean. Rotate pans once if your oven bakes unevenly.
Let the cakes cool in the pans for 10 minutes, then remove them to wire racks and cool completely.
Place one cake layer on a cake plate or cardboard round. Spread about one-third of the strawberry frosting evenly over the layer, then arrange a layer of sliced strawberries on top of the frosting.
Set the second cake layer on top, frost the top and sides with the remaining strawberry frosting, then pour or spread the chocolate ganache over the top, allowing some to drip down the sides if desired.
Decorate with additional strawberries as desired; for an extra touch, dip whole strawberries in some ganache before placing them on the cake.
Refrigerate the assembled cake until ready to serve and bring to room temperature before slicing.