Step 1

Prep your oven and pans. Position a rack in the center of the oven and preheat the oven to 350°F. Generously spray three 8-inch round cake pans with cooking spray and line the bottom of each with a parchment paper circle. Spray the parchment, too.

Step 2

Make the cake batter. In a medium bowl, whisk together the sugar, flour, cocoa powder, baking powder, baking soda, and salt.

Step 3

In a large bowl, whisk together the milk, oil, eggs, and vanilla. Gradually whisk in the dry ingredients until just combined. Slowly pour in the water. The batter will be fairly runny; use a rubber spatula to scrape down the bottom and sides of the bowl. Use the rubber spatula to finish mixing until smooth and well combined, 2 to 3 minutes more.

Step 4

Divide the batter evenly between the pans; if using a digital scale to measure out layers, note that this recipe makes around 48 ounces (1361 grams) of batter—pour 16 ounces (454 grams) of batter into each cake pan.

Step 5

Bake the cakes. Bake for 30 to 35 minutes. When done, the top of the cake should bounce back when gently pressed. A skewer inserted into the center of the cake should come out with a few crumbs attached. Cool completely in the pans on a wire rack before frosting.

Step 6

Store the cakes. Once the cakes are cool, tightly wrap each cake layer in its own sheet of plastic wrap. Freeze overnight, or up to 3 months.

Step 7

Thaw the cakes. When ready to assemble the cake, remove the cakes from the freezer. Unwrap each cake and discard the plastic wrap. Set aside to thaw slightly while you make the frosting.

Step 8

Prep the ingredients for the chocolate frosting. Sift together the confectioners' sugar, cocoa powder, and salt into a medium bowl. In a small liquid measuring cup, whisk together the milk and vanilla.

Step 9

Make the chocolate frosting. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter on medium-low until smooth and creamy, about 1 minute. Reduce the mixer to low and gradually add the dry ingredients, beating until combined. Scrape down the bottom and sides of the bowl with a rubber spatula. With the mixer on low, slowly pour in the milk and vanilla and beat until just combined. Scrape down the bottom and sides of the bowl once more, then beat on medium-high until the frosting is creamy and smooth, 2 to 3 minutes. Use immediately.

Step 10

Assemble the cake. If necessary, level the top of the cakes. Place one of the cake layers on a cake board or serving platter in the center of a rotating cake stand. Use a rubber spatula or cookie dough scoop to drop ½ cup of frosting in the middle of this cake layer. Use an offset spatula to spread it evenly all over the top, just like you would spread butter on toast. Place the second cake on top of this frosting, stacking it evenly on top of the first cake. Use the rubber spatula or cookie dough scoop to drop another ½ cup of frosting in the middle of this cake layer. Spread it evenly all over the top. Finally, place the third cake on top of this frosting, stacking it evenly on top of the first two cakes.

Step 11

Next, crumb coat the cake. Use the offset spatula to cover the surface of the entire layer cake with a thin layer of frosting. Use just enough frosting to cover the entire cake completely. Refrigerate, uncovered, for 10 to 15 minutes to stiffen and "set" the frosting.

Step 12

After the crumb coat sets, finish frosting the cake. Use the offset spatula to cover the cake with the remaining frosting. Then, use the spatula to make large, random sweeping motions across the frosting on the top and sides of the cake. The sweeping motions will create swirls.

Step 13

Serve and store. Serve immediately. The assembled Hershey's Perfectly Chocolate Cake can be stored at room temperature, under a cake dome or a large bowl turned upside down, for up to 1 day. Press a sheet of plastic wrap against any cut surfaces to prevent the cake from drying out. After that, cover the entire cake loosely with plastic wrap and refrigerate for up to 2 days.