Homemade Three-layer Sheet Carrot Cake Recipe

Preparation

Preheat the oven to 350°F (175°C). Prepare three 9x13-inch sheet pans by lightly greasing the bottoms and sides with butter or nonstick spray and line with parchment paper, leaving a 1-inch overhang on two sides for easy removal.

Dry ingredients

In a very large bowl (or in a stand mixer bowl), whisk together 6 cups all-purpose flour, 3 cups granulated sugar, 1 cup packed light brown sugar, 3 tsp baking powder, 3 tsp baking soda, 3 tsp fine salt, 3 tsp ground cinnamon, 1 tsp ground nutmeg, and 1 tsp ground ginger until evenly combined.

Wet ingredients

In a separate large bowl, whisk 3 cups vegetable oil with 9 large eggs until smooth. Add 3 tbsp vanilla extract and 1 1/2 cups whole milk (or buttermilk) and whisk to combine.

Combine wet and dry

Pour the wet mixture into the dry ingredients and stir with a sturdy spatula or use the paddle attachment on low speed just until combined and no large streaks of flour remain. Do not overmix.

Add carrots, pineapple, nuts and raisins

Fold in 9 cups packed grated carrots, 2 cups drained crushed pineapple (pat dry to avoid thinning the batter), 2 cups chopped walnuts or pecans (if using) and 1 cup raisins (if using) until evenly distributed. The batter will be thick and moist.

Divide and bake

Divide the batter evenly among the three prepared 9x13 pans (use a kitchen scale or measure approximate thirds). Smooth the tops with an offset spatula to even thickness. Bake one sheet at a time or all three racks if your oven allows even heat: bake at 350°F (175°C) for 20–26 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs and the top springs back when lightly pressed. Rotate pans halfway through if baking multiple pans on different racks for even browning.

Cool

Remove pans from oven and let cool on wire racks for 15 minutes. Run a thin knife around the edges, lift cakes using the parchment overhang and transfer to racks to cool completely (about 1–1.5 hours) before frosting. If layers dome slightly, trim to level with a serrated knife or cake leveler.

Beat butter and cream cheese

In a large bowl or stand mixer fitted with the paddle attachment, beat 1.5 cups room-temperature unsalted butter and 36 oz room-temperature cream cheese on medium speed until smooth and fully combined, about 2–3 minutes. Scrape down the bowl as needed.

Add sugar and flavor

Reduce mixer to low and gradually add 9 cups sifted confectioners' sugar, about 1 cup at a time, beating briefly after each addition to avoid a powdered-sugar cloud. Once incorporated, add 2 tbsp vanilla extract, 1/2 tsp fine salt, and 1 tbsp lemon juice (if using). Increase speed to medium-high and beat until light, fluffy, and spreadable, about 2 minutes. If frosting is too stiff, add 1–2 tbsp milk at a time to reach desired consistency; if too loose, add 1/2 cup more sifted sugar.

Taste and adjust

Taste the frosting and adjust salt or lemon to balance sweetness. Chill briefly (10–15 minutes) if frosting becomes too soft to work with.

Level and place first layer

Place one cooled cake sheet (bottom side down) on a long flat serving board or another 9x13 pan acting as a base. If needed, trim to make the edges square. Spread about one-third of the frosting in an even layer (about 1/3 of total frosting) over the first sheet, leaving a 1/4-inch border if coating the sides later.

Stack

Carefully place the second cake sheet on top of the frosted first layer. Press gently to create full contact. Spread another third of the frosting evenly over the second layer. Add the third sheet and press lightly to level.

Crumb coat

Using an offset spatula, apply a thin crumb coat of frosting (about 1/4 of the remaining frosting) over the top and sides to seal in crumbs. Chill the assembled cake in the refrigerator for 20–30 minutes to set the crumb coat.

Final frosting

Remove the cake from the fridge and finish with the remaining frosting, smoothing the top and sides with an offset spatula for a clean look. If you want textured swirls, use the back of a spoon or spatula to create patterns on the top.

Garnish

Sprinkle 1/2 cup extra chopped nuts around the edges or in the center, scatter 1/2 cup toasted coconut flakes if using, and arrange 1/2 cup grated carrot or carrot ribbons as decorative accents. Refrigerate for 30 minutes to set before serving, or serve immediately at room temperature.

Storage

Store leftover cake covered in the refrigerator for up to 4–5 days (cream cheese frosting requires refrigeration). For longer storage, freeze individual slices tightly wrapped for up to 2 months; thaw overnight in the refrigerator before serving.