Preheat oven to 350°F (176°C) and prepare three 8-inch cake pans with non-stick baking spray and parchment paper.
In a large mixer bowl, combine flour, sugar, cocoa, baking soda, baking powder, and salt. Set aside.
In a medium bowl, whisk together milk, vegetable oil, vanilla extract, and eggs.
Add wet ingredients to dry ingredients and beat until well combined.
Slowly add hot water to batter and mix on low speed until smooth.
Divide batter evenly among prepared pans and bake for 22–25 minutes, or until a toothpick comes out clean.
Cool cakes in pans for 2–3 minutes, then transfer to a wire rack to cool completely.
Make the coconut filling by mixing sweetened condensed milk and shredded coconut in a bowl. Stir until combined.
For the frosting, cream butter and shortening together until smooth.
Gradually add half of the powdered sugar and mix until incorporated.
Add coconut extract and 4–5 tablespoons of water or milk; mix until smooth.
Add remaining powdered sugar and mix until fluffy. Adjust consistency with more liquid if needed.
Level the cooled cake layers using a serrated knife so they are flat.
Place first layer on a serving plate and pipe a ring of frosting around the edge as a dam.
Fill the center with half of the coconut mixture and spread evenly.
Sprinkle sliced almonds over the filling and press gently into place.
Repeat with second layer: add frosting dam, coconut filling, and almonds.
Top with the final cake layer.
Apply a thin crumb coat of frosting to the sides and chill for 15 minutes.
Frost the entire cake smoothly, creating decorative stripes on the sides.
Prepare chocolate ganache: microwave heavy cream until steaming, pour over chocolate chips, let sit 2–3 minutes, then whisk until smooth.
Drizzle ganache around the edges and over the top of the cake using a squeeze bottle or spoon.
Let ganache set slightly (about 10 minutes), then finish decorating with extra frosting, coconut, almonds, and Almond Joy candy bars.
Refrigerate cake until ready to serve. Best served at room temperature. Keeps well for 3–4 days.