Place the flour, sugar, cocoa powder, baking powder, baking soda, and salt into the stand mixer bowl (or a large bowl if mixing by hand) and use the paddle attachment to mix the ingredients together on the lowest setting until combined.

Slowly pour in the oil with the mixer running at low speed and continue mixing until all of the dry ingredients are moistened and crumbly.

In a liquid measuring cup or medium bowl, whisk together the eggs, whole milk, and vanilla. Slowly pour the wet ingredients into the stand mixer while it is running at low speed. The cake batter will be loose at this point. If you have a splatter shield for your stand mixer, use that now.

Start with approximately 6 cups (900g) of room-temperature unflavored Italian Meringue Buttercream. Add approximately 1 cup (320g) of room-temperature caramel (or an amount to your taste) and stir with a spatula to combine. Keep in mind that the more caramel you add, the looser the buttercream will be. If the ingredients are not at room temperature, you will end up with very soft or melted buttercream (if using hot caramel) or chunks of caramel that do not fully incorporate into the frosting (if using cold caramel or buttercream).

If you have any cake humps/domes, use a serrated knife to level each cake. Then, cut each layer of cake in half to make 4 layers of chocolate cake.

Using an offset spatula, spread a small amount of buttercream in the middle of the cake board (or serving platter) to act as glue and place one cake layer on top of the board. Smooth a thin amount of buttercream over the top of the cake layer and pipe a dam or ring of buttercream around the edge of the cake. To do this, place some caramel buttercream into a piping bag (or plastic zip-top bag) and cut off the tip to leave a large hole. Then, squeeze the bag while moving your hand around the edge of the cake.

Using a cleaned offset spatula, frost the sides and top of the cake using more caramel buttercream. Scrape the sides and top with the edge of your offset spatula to get a smooth finish. Then, use a textured cake comb to add a ridged pattern to the side of the cake.

Place the frosted cake into the fridge for the buttercream to harden. This will be important for getting a nice drip.

Place the remaining caramel buttercream in a piping bag fitted with a 1M tip and set aside.

Before finishing the cake decorations, you will need to prepare the toppings. Start by making the chocolate drip.

Place the chopped chocolate into a heat resistant bowl (metal or glass).

Use a spatula to mix the chocolate and cream together until it is smooth and glossy without any remaining chocolate pieces. This is now a liquid chocolate ganache.

Take the chocolate ganache and repeat the same drip process around the top of the cake with the chocolate.

Leave the middle of the top of the cake uncovered by caramel or chocolate.

Using the caramel buttercream, pipe 12 swirls on the top of the cake. To keep the swirls evenly placed, I like to start by piping the swirls at 12, 3, 6, and 9 (if thinking of the top of the cake as the face of a clock). 2 swirls will then fit between each of the original swirls. Finish by topping each swirl with chopped pecans and add chopped pecans to the middle of the cake as well.

Serve this cake at room temperature for the best flavor and texture. To get clean slices, dip your knife in hot water and wipe off any cake residue in between each slice.

Keep the turtle cake in an airtight container (e.g., a cake keeper or a covered cake plate). It will stay fresh up to 3 days at room temperature for up to 5 days in the fridge. If you store the cake in the fridge, allow it to come to room temperature before serving (i.e., let it sit at room temperature for at least 1 hour before serving). The butter in the frosting will harden in the fridge so it will have a crumbly and firm texture if eaten directly from the fridge.