Preheat the oven to 350°F (175°C). Spray three 8-inch (20 cm) round cake pans with nonstick spray, line the bottoms with parchment circles, and spray again.
cooking spray
Grate the carrots using a food processor or box grater. Measure 5 cups (250g) and set aside. (Do not use pre-shredded carrots.)
5 cups (250 g) grated carrots
In a medium bowl, whisk together the flour, baking powder, baking soda, kosher salt, ginger, nutmeg, and cloves until evenly combined.
3 cups (360 g) all-purpose flour, 1 tbsp (12 g) baking powder, 1 tsp (6 g) baking soda, 1 tsp (2 g) kosher salt, 1 tsp (2 g) ground ginger, ½ tsp (1 g) ground nutmeg, ½ tsp ( 1 g) ground cloves
In a large bowl or stand mixer, beat the butter on high speed until lightened in color and fluffy, about 2 minutes. Add the granulated sugar and brown sugar and continue beating on high speed for about 3 minutes, until fully combined and airy. Add the eggs one at a time, mixing well after each addition, then add the vanilla and beat until smooth. Scrape down the sides and bottom of the bowl as needed.
1 cup (226 g) unsalted butter, 1 cup (198 g) granulated sugar, ½ cup (106 g) light brown sugar, 4 large eggs, 1 tsp (5 ml) vanilla extract
Add one-third of the dry ingredients and mix on low speed just until mostly combined. Add half of the sour cream and mix on low until just incorporated. Add another third of the dry ingredients, followed by the remaining sour cream, then the final third of the dry ingredients, mixing on low speed and stopping as soon as the batter comes together. Fold in the grated carrots with a spatula until evenly distributed.
1 cup (227 g) full-fat sour cream
Divide the batter evenly between the prepared pans, filling each pan about two-thirds full (16 to 17 ounces / 615 to 620g per pan), and smooth the tops.
Bake on the center rack for 23 to 27 minutes, or until the tops spring back lightly when touched and a toothpick inserted into the center comes out with a few moist crumbs.
Remove from the oven and allow the cakes to cool completely in the pans to retain moisture and keep the layers level.
To make the white chocolate cream cheese buttercream, combine the white chocolate and heavy cream in a microwave-safe bowl and heat for 30 seconds. Stir until smooth, then continue heating in 10 to 15 second intervals if needed until fully melted. Set aside and allow to cool to room temperature.
3 oz (85 g) white chocolate, 2 tbsps (30 g) heavy cream
In a medium bowl, beat the butter and cream cheese on high speed until smooth and fluffy. Add the cooled white chocolate mixture and beat until fully incorporated. Add the confectioners' sugar, kosher salt, and vanilla. Mix on low speed until combined, then increase to high speed and beat until light and spreadable.
¾ cup (170 g) unsalted butter, 2 oz (57 g) full-fat cream cheese, 3¼ cups (367 g) confectioners' sugar, ½ tsp (3 g) kosher salt, 1 tsp (5 ml) vanilla extract
Place one cooled cake layer on a cake stand or plate, top side up. Spread about ½ cup (120g) of buttercream evenly over the surface, taking it to the edges. Spoon ¼ cup (80g) of apricot preserves over the buttercream and spread evenly.
1 jar (11.8 oz / 335 g) apricot preserves
Place the second cake layer on top, top side up, and repeat with another ½ cup (120g) buttercream followed by ¼ cup (80g) apricot preserves.
Place the third cake layer on top, top side up. Spread about ¼ cup (60g) buttercream in the center of the cake, leaving a border around the edges. Transfer the remaining buttercream to a piping bag fitted with a large star tip and pipe a border around the top edge of the cake. Spoon about ½ cup (160g) apricot preserves into the center and gently spread to fill the space within the buttercream border.
Let the cake sit briefly before serving to allow the buttercream to set slightly.