Homemade Little Debbie Christmas Tree Cakes

Preheat oven to 400°F. Spray a 18x13-inch rimmed baking sheet with cooking spray; line with parchment paper. Spray paper with cooking spray.

Beat egg yolks and 1 cup of the sugar with a heavy duty electric stand mixer on high speed until thick and pale, about 2 to 3 minutes. Beat in vanilla.

Using clean, dry beaters and a clean bowl, beat egg whites and cream of tartar on medium speed until foamy. Increase speed to high, and beat until soft peaks form. Add remaining 1/2 cup sugar gradually, beating on high speed until stiff peaks form. Fold one-fourth of the egg white mixture into egg yolk mixture until just combined, then fold in remaining three-fourths egg white mixture.

Stir together cake flour, baking powder, and salt. Sift one-third of the flour mixture over egg mixture. Fold gently until just blended, then fold in remaining two-thirds of flour mixture. Spread batter gently in prepared pan, taking care not to deflate batter.

Bake in preheated oven until puffed and lightly browned on top, 11 to 13 minutes. Run a small offset spatula around edges of pan to loosen; cool in pan 2 minutes. Invert onto a wire rack to cool completely, about 30 minutes.

Using a 31/2 or 4-inch Christmas tree cookie cutter, cut out 16 tree shapes from cake. Discard any scraps. Spread about 2 tablespoons of buttercream on 8 of the cut out trees, then top with remaining 8 trees to create 8 cake sandwiches. Place sandwiches on a wire rack fitted into a rimmed baking sheet.

Melt candy wafers according to package directions. Pour melted candy coating evenly over cakes, being sure to coat each cake evenly. If needed, scrape any excess candy coating back into bowl and pour over cakes again to coat fully. Sprinkle with green sanding sprinkles. Place baking sheet in refrigerator and chill until candy melts are set, about 20 minutes.

Snip the tip of decorating icing and drizzle over Christmas Tree Cakes to create a red garland pattern. Let sit until red garland is set, about 1 hour at room temperature. Store in an air-tight container up to 5 days.