沒有第四個放假的燒烤或慶祝活動，怎麼能缺少一道甜點呢？這款由開發者 Katie Rosenhouse 所設計的美國國旗「切片揭露」蛋糕，正是這次場合的重頭戲。蛋糕外表看起來相當愛國，因為巧妙使用裝飾性的紅、白、藍色蛋糕屑，但真正的魔法在於你切下一塊時，會現出內部層層堆疊的美國國旗圖樣，幾乎美得讓人捨不得吃掉。
當然，除了具愛國色彩與震撼視覺層次之外， Rosenhouse 也向我們保證，這道喜慶甜點其實相當容易做。「這是一款非常有趣的蛋糕，而且做起來出乎意料地簡單，」她說道。「一份蛋糕麵糊可以化為三層不同的紅、白、藍色蛋糕，從中心簡單挖出一個洞就能在中間露出那個旗幟揭露圖案。」在你完成烘焙、切割、分層與裝飾的過程中，或許需要多一點耐心，但這是那種最終成品會把成果放在最前端展示的食譜。
當然，除了愛國色彩與令人印象深刻的分層之外，這也僅僅是一道美味的蛋糕食譜，擁有香濃香草口味與豐富的奶油霜。 Rosenhouse 將其形容為「美味且鬆軟平衡的蛋糕」，絕對足以成為你第四七月甜點拼盤的 centerpiece。
Gather the ingredients for this American flag ‘slice and reveal’ cake
就蛋糕本身而言，你需要軟化的無鹽奶油、植物油、砂糖、香草豆莢膏或香草精、雞蛋、通用麵粉、泡打粉、 kosher 鹽、小蘇打，以及酪乳。這個麵糊將作為蛋糕三層的底層，因此你還需要紅色與藍色凝膠型食品色素，讓顏色活起來。
否則，唯一需要的原料就是糖霜本身：軟化的無鹽奶油、軟化的奶油乳酪、糖粉、香草豆莢膏或香草精，以及 kosher 鹽。你可以按需再加些裝飾用的糖珠，但 Rosenhouse 巧妙地用已弄碎的蛋糕屑在蛋糕外側創造出像糖屑的花紋，因此不需要額外的材料。
Step 1: Preheat the oven
預熱烤箱至華氏 350 度（約 177 攝氏度）。
Step 2: Prepare the cake pans
噴油並在三個 8 吋的蛋糕模內鋪上烘焙紙。
Step 3: Begin the cake batter
在立式攪拌機的攪拪裝置中加入軟化的奶油、油、糖和香草，打至混合均勻。
Step 4: Add the eggs
一次加入兩顆雞蛋，並在每次加入後攪拌至混合均勻。
Step 5: Mix in the dry ingredients
加入麵粉、泡打粉、鹽、小蘇打與酪乳，拌勻至混合。
Step 6: Portion out the cake batter
將大約 3 杯麵糊分裝到兩個碗中，各自大致成為 3 杯左右。
Step 7: Mix in blue and red food coloring
把其中一碗拌入藍色，另一碗拌入紅色，以達到你想要的色調。
Step 8: Spread the cake batter into pans
把藍、紅、白三種麵糊分別倒入蛋糕模中，均勻抹平。
Step 9: Bake the cakes
以 45–50 分鐘烘烤，直到中心插入木籤後取出乾淨為止。
Step 10: Unmold the cakes
放涼一會兒，然後移出模具，放在冷卻架上完全冷卻。（如果時間充裕，冷藏至冷硬再切片，會更容易切割。）
Step 11: Beat butter and cream cheese
等蛋糕完全冷卻後，開始準備糖霜。把奶油與奶油乳酪打至混合。
Step 12: Add the remaining frosting ingredients
先加入半數糖粉、香草與鹽，攪拌至均勻。
Step 13: Add the remaining sugar
把剩餘的糖粉加入，低速攪拌混合，然後提高速度攪打至輕盈蓬鬆。
Step 14: Slice the cakes into thinner layers
用鋸齒刀把白色蛋糕分成三層，紅色蛋糕分成兩層。
Step 15: Cut the centers out of some of the cake layers
使用直徑 4 1/2 或 5 吋的圓形模切器，將其中一個白色蛋糕層、一個紅色蛋糕層與藍色那層的中心挖出。如果沒有模切器，可以找碟子或碗沿著邊緣畫圈再用刀切出圓形。
Step 16: Transfer some of the cake scraps to a separate bowl
把外圈的紅白蛋糕屑轉移到碗中，以及藍色蛋糕的中心也一起放進碗裡。
Step 17: Transfer frosting to a piping bag
把一半的糖霜轉移到擠花袋中。
Step 18: Begin layering the cake
將白色蛋糕層放在餐盤或蛋糕板上，均勻覆上一層薄薄的糖霜。
Step 19: Add a red layer
以紅色蛋糕層作為頂層並重複一次。
Step 20: Add a blue and red layer
以藍色的外圈覆蓋蛋糕，然後在中間放置一圈圓形紅色蛋糕。
Step 21: Add frosting and a white cake layer
在紅色蛋糕中心覆上一層薄薄的糖霜，並再覆上一層白色蛋糕。
Step 22: Crumb coat and chill the cake
用薄層糖霜覆蓋整個蛋糕，作為碎屑包覆層，然後冷藏至定型。
Step 23: Crumble cake scraps
把約一半的蛋糕屑搗碎，做成裹在蛋糕外層的覆蓋物與裝飾配料。
Step 24: Transfer frosting to a piping bag with a star tip
把大約 1 1/2 杯糖霜轉移到裝有星形花嘴的擠花袋中。
Step 25: Press crumbs onto the cake
以剩餘糖霜 coating 輪切蛋糕的側邊，並按上蛋糕屑以覆蓋整個蛋糕。
Step 26: Pipe rosettes onto the cake
在蛋糕頂部邊緣擠出花朵形狀的裝飾花紋。
Step 27: Add another frosting border and more crumbs
在蛋糕底部繪出一個邊框，並以剩餘的麵屑充填中央。
Step 28: Decorate and serve the cake
添加任何你喜歡的裝飾物，然後上桌享用或放入冰箱冷藏保存。
What can I serve with this American Flag cake for a party?
American Flag ‘Slice and Reveal’ Cake Recipe
這道美味且壯觀的美國國旗「切片揭露」蛋糕，肯定會在你舉辦獨立日聚會或野餐時成為人群的焦點。
Total time: 3 hours, 10 minutes
- For the cake
- 1 cup unsalted butter, softened
- ½ cup vegetable oil
- 2 ¾ cups granulated sugar
- 2 teaspoons vanilla bean paste or extract
- 5 large eggs
- 3 ¾ cups all-purpose flour
- 2 teaspoons baking powder
- 1 ½ teaspoons kosher salt
- 1 teaspoon baking soda
- 2 cups whole buttermilk
- Red and blue gel food coloring, as desired
- For the frosting
- 1 cup unsalted butter, softened
- 1 (8-ounce) package cream cheese, softened
- 6 cups confectioners’ sugar, divided
- 1 teaspoon vanilla bean paste or extract
- ½ teaspoon kosher salt
- Preheat the oven to 350 F.
- Spray and line three 8-inch cake pans with parchment paper.
- In the bowl of a stand mixer fitted with a paddle attachment, beat the butter, oil, sugar, and vanilla until combined.
- Add the eggs one at a time, mixing until combined between each addition.
- Add the flour, baking powder, salt, baking soda, and buttermilk, and mix to combine.
- Transfer about 3 cups of batter into each of two bowls.
- Mix blue color into one bowl, and red color into the other to reach your desired shade.
- Transfer the blue, red, and white batters into cake pans and spread evenly.
- Bake for 45-50 minutes, or until a wooden pick inserted in the centers comes out clean.
- Cool slightly, then unmold onto a cooling rack and cool completely. (If you have time, chill until cold for easier slicing.)
- Once the cakes are cool, prepare the frosting. Beat butter and cream cheese to combine.
- Add half the confectioners’ sugar, vanilla, and salt, and beat until uniform.
- Add the remaining confectioners’ sugar and beat on low speed to combine, then increase the speed and beat until light and fluffy.
- Use a serrated knife to divide the white cake into three layers, and the red cake into two layers.
- Use a 4 ½ or 5-inch round cutter to cut out the center of one white cake layer, one red cake layer, and the blue layer. If you don’t have a cutters, trace a plate or bowl and use a knife to cut out the rounds.
- Transfer the outer ring of the red and white cakes to a bowl, along with the center of the blue cake.
- Transfer half of the frosting into a piping bag.
- Place a white cake layer onto a serving plate or cake board, and top it evenly with a thin layer of frosting.
- Top with a red cake layer and repeat.
- Top with the blue ring of cake, then place a round of red cake in the center.
- Top the red cake center with a thin layer of frosting, and top with the white cake round.
- Coat the cake with a thin layer of frosting as a crumb coat. Chill until firm.
- Crumble about half of the cake scraps in a bowl to create a coating and topping for the cake.
- Transfer about 1 ½ cups of frosting to a piping bag fitted with a star tip.
- Coat the sides of the cake with any remaining frosting, and press on cake crumbs to coat.
- Pipe rosettes around the border of the top of the cake.
- Pipe a border around the base of the cake and fill the center with the remaining crumbs.
- Add any desired toppers and serve or store in the refrigerator.
| Calories per Serving | 773 |
| Total Fat | 37.7 g |
| Saturated Fat | 18.8 g |
| Trans Fat | 0.2 g |
| Cholesterol | 136.8 mg |
| Total Carbohydrates | 104.5 g |
| Dietary Fiber | 0.9 g |
| Total Sugars | 80.6 g |
| Sodium | 484.8 mg |
| Protein | 7.2 g |
The information shown is Edamam’s estimate based on available ingredients and preparation. It should not be considered a substitute for a professional nutritionist’s advice.
Can I make this cake ahead?
雖然這款蛋糕的設計相當壯觀，實際上做起來也頗為費工，從烘焙、冷藏、分層到糖霜裝飾都需要時間。不過 Rosenhouse 保證，這款蛋糕確實具備提前製作的潛力，無論你是在週初就先做層或是接近完成整體再進行收尾裝飾。
開始的簡單方式是先把蛋糕層烤好，讓工作先一步完成：「你可以先把蛋糕層烤好——冷卻、密封包好，放入冷藏最多兩天，或冷凍最多兩個月再切片與組裝。」Rosenhouse 建議。為了保持層的最大新鮮度，包裝前要確保它們完全冷卻（以避免過多凝結），並用保鮮膜雙層包裹以確保水分鎖住。
你甚至可以提前幾天完成整個蛋糕，直到最終的花朵狀 rosette 邊框都完成為止。只要照原本配方進行，並在計畫上餐前切片與上桌前，於兩天內放入冰箱冷藏，讓蛋糕稍微回溫至室溫，即可切片享用。
What are tips for making a successful slice and reveal cake?
如果你被這款蛋糕的多層結構感到不知所措，其實你並不孤單——Rosenhouse 有一些專業技巧，可以確保你的切片揭示蛋糕確實像美國國旗一樣。這一切都從給自己充裕時間開始，因為這類食譜並非隨興就能完成。若你有多一點時間讓蛋糕層冷卻，整個過程會更容易。她解釋道：「如果你能在切片前冷藏蛋糕層，它們會更易處理，層疊時也不易碎。」
另外，Rosenhouse 為什麼要把糖霜轉移到擠花袋，而不是直接從碗倒在蛋糕上？「由於層與層是切片的，使用擠花袋擠糖霜也能避免在內餡中混入蛋糕屑。」她說。關於切片蛋糕的層，請確保你在切割時動作穩定緩慢，讓每層都盡量保持平整。最後，外觀（尤其是糖霜在外部的樣子）不必完美，因為你最終會覆以屑屑，整體外觀就會自然而然地成型。
