Go Back
–+ servings

Easy Graduation Party Sheet Cake in School Colors

Annahita Carter
An easy 9×13-inch vanilla sheet cake with creamy buttercream that decorates quickly in school colors with tinted frosting and sprinkles—perfect for feeding a small crowd and easy to slice and transport.
No ratings yet
Print Recipe Start Cooking Pin Recipe
Prep Time 30 minutes
Cook Time 32 minutes
Resting Time 1 hour 50 minutes
Total Time 2 hours 52 minutes
Course Dessert
Cuisine American
Servings 18 servings
Calories 360 kcal

Equipment

  • 9×13-inch metal baking pan
  • Parchment paper
  • Large mixing bowl
  • Whisk
  • Stand mixer or hand mixer
  • Rubber spatula
  • Offset spatula
  • Wire rack
  • Piping bag with star or round tip (optional)

Ingredients
  

For the vanilla sheet cake

  • 290 g all-purpose flour spooned and leveled
  • 300 g granulated sugar
  • 2 1/2 tsp baking powder
  • 1/2 tsp baking soda
  • 3/4 tsp fine sea salt
  • 170 g unsalted butter very soft but not melted
  • 60 ml neutral oil canola or sunflower
  • 3 large eggs room temperature
  • 1 large egg white room temperature
  • 240 ml buttermilk room temperature
  • 2 1/2 tsp pure vanilla extract

For the vanilla buttercream frosting

  • 340 g powdered sugar sifted
  • 225 g unsalted butter softened
  • 45–60 ml heavy cream or whole milk
  • 2 tsp pure vanilla extract
  • 1/4 tsp fine sea salt

For school color decoration

  • 1–2 gel food coloring school colors, for tinting part of the frosting
  • 60–90 g sprinkles or nonpareils in school colors
  • pre-made sugar letters or chocolate letters optional, for the graduation year and name

Instructions
 

  • Preheat oven to 350°F (175°C). Lightly grease a metal 9×13-inch baking pan, line the bottom with parchment, and grease again if desired. If using a glass pan, reduce oven temperature by 25°F (about 10–15°C) and expect a slightly longer bake.
  • In a large bowl, whisk together the flour, baking powder, baking soda, and salt until evenly combined. Set aside.
  • In a stand mixer bowl (or large bowl with a hand mixer), beat the very soft butter and sugar on medium-high for 3–4 minutes until pale and fluffy. Scrape down the bowl, add the oil and vanilla, and beat 30–60 seconds until incorporated.
  • Add the eggs one at a time, beating on medium for 20–30 seconds after each addition. Add the egg white last and mix just until combined; scrape the bowl and beat about 15 seconds more.
  • With the mixer on low, alternate adding the dry ingredients and buttermilk: add about 1/3 of the dry mix, then 1/2 the buttermilk; repeat with another 1/3 dry, remaining buttermilk, and finish with the last 1/3 dry. Mix only until each addition is just absorbed.
  • Turn off the mixer and finish by hand with a spatula, folding from the bottom to ensure no flour pockets remain. Stop as soon as the batter is smooth and no dry flour is visible.
  • Pour batter into the prepared pan and spread evenly (an offset spatula helps). Tap the pan gently on the counter to release large air bubbles. Bake on the center rack 25–32 minutes, rotating once halfway if needed, until the top springs back and a toothpick in the center comes out clean or with a few moist crumbs.
  • Cool the cake in the pan on a wire rack 20–30 minutes. For serving from the pan, cool completely in the pan (about 1–1½ hours). For removing, run a knife around edges, invert onto a rack, peel parchment, and cool fully.
  • Make the buttercream: in a clean mixer bowl, beat softened butter on medium-high for 2 minutes until light. Add half the sifted powdered sugar and mix on low to combine, then beat 1 minute on medium. Add remaining powdered sugar, vanilla, salt, and 3 Tbsp cream/milk; beat 2–3 minutes on medium-high until fluffy, adding up to 1 more Tbsp cream/milk if needed for a spreadable consistency.
  • Reserve about 1/4–1/3 of the frosting for piping in a separate bowl. Tint the reserved portion with gel food coloring, starting with a tiny amount and adding gradually until you reach the desired school color(s).
  • Frost the cooled cake: spread the untinted buttercream evenly over the top. If your kitchen is warm, chill the frosted cake 10–15 minutes to firm the surface before adding colored details.
  • Decorate: transfer tinted frosting to a piping bag with a star or round tip (or a zip-top bag with a corner snipped). Pipe a border around the edges, add the graduate’s name/year with tinted frosting or pre-made letters, and add school-colored sprinkles along the border or across part of the cake.
  • Chill the decorated cake 20–30 minutes for neat slices before serving. For transport, chill at least 1 hour and keep covered in a snug cake box or lidded pan.

Nutrition

Calories: 360kcalCarbohydrates: 46gProtein: 4gFat: 18gSaturated Fat: 10gCholesterol: 75mgSodium: 210mgPotassium: 80mgFiber: 1gSugar: 32gVitamin A: 520IUCalcium: 55mgIron: 1.3mg
Tried this recipe?Let us know how it was!
QR Code linking back to recipe