Christmas Tree Cake

Prepare the Cake: Preheat oven to 350°F. Beat butter with a stand mixer fitted with a paddle attachment on medium speed until creamy, about 1 minute. Gradually add sugar; beat until light and fluffy, 2 to 3 minutes. Add eggs 1 at a time, and beat just until incorporated after each addition, about 1 minute total. Beat in lemon juice and vanilla until combined, about 15 seconds. Scrape down sides and bottom of bowl using a flexible spatula.

Whisk together flour and baking soda in a small bowl until combined. Add flour mixture to butter mixture alternately with buttermilk in 4 additions, beginning and ending with flour mixture, beating on low speed just until combined after each addition.

Coat a 13-by-9-inch baking pan with baking spray, and line with parchment paper, leaving a 3-inch overhang on long sides. Lightly coat parchment paper with baking spray. Pour batter into prepared pan. Bake in preheated oven until a wooden pick inserted into center of cake comes out clean, 30 to 35 minutes. Let cool in pan on a wire rack 15 minutes. Remove cake from pan using parchment paper overhang as handles, and transfer to wire rack; let cool completely, about 1 hour.

Prepare the Frosting: Beat cream cheese and butter with a stand mixer fitted with a paddle attachment on medium speed until creamy, about 1 minute. Reduce mixer speed to low, and gradually add powdered sugar, beating until incorporated, about 3 minutes. Increase mixer speed to medium, and beat frosting until fluffy, adding lemon juice, 1 teaspoon at a time, until desired consistency.

Measure 1 cup frosting into a small bowl, and set aside. Add 1 to 2 drops green food coloring gel to remaining frosting in mixing bowl; beat on medium speed until fully incorporated, adding additional gel if needed to reach desired shade of green.

Assemble the Cake: Place cake on a platter. Using a serrated knife, cut cake into a triangular Christmas tree shape. Cut cake scraps into a tree trunk base and assorted-size presents. Frost top and sides of Christmas tree with green-dyed frosting. Attach cake base; frost base top and sides with green-dyed frosting.

Sprinkle cake base with gold sugar pearls to completely cover top and sides. Sprinkle Christmas tree lightly with white sparkling sugar. Decorate cake with red decorating gel to resemble a light string. Attach green chewy candy halves to top of peanut candy pieces, pressing lightly to adhere to candy. Attach assembled candy lights to red string to resemble Christmas lights. Randomly press candy stars onto tree to resemble decorations.

Frost top and sides of cake presents with reserved undyed white frosting. Pipe bows and ribbons onto presents using red and green decorating gel.