Big Vanilla Sheet Cake with Buttercream Frosting

Big Vanilla Sheet Cake with Buttercream Frosting

Cake Ingredients:

• 3 cups (375g) all-purpose flour
• 2 ½ teaspoons baking powder
• ½ teaspoon baking soda
• ½ teaspoon salt
• 1 cup (226g) unsalted butter, softened
• 2 cups (400g) granulated sugar
• 4 large eggs, room temperature
• 1 tablespoon vanilla extract
• 1 ½ cups (360ml) whole milk, room temperature
• ½ cup (120ml) sour cream (for extra moisture)

Buttercream Frosting Ingredients:

• 1 ½ cups (340g) unsalted butter, softened
• 6 cups (720g) powdered sugar, sifted
• 1 tablespoon vanilla extract
• ¼ teaspoon salt
• 4–6 tablespoons heavy cream or milk (for desired consistency)

Instructions:

Step 1: Prepare the Cake

1. Preheat oven to 350°F (175°C). Grease and flour a 9×13-inch sheet pan (or line with parchment).
2. In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
3. In a large bowl, beat butter and sugar together until light and fluffy (about 3–4 minutes).
4. Add eggs one at a time, beating well after each addition. Mix in vanilla.
5. Mix in sour cream.
6. Add the flour mixture in 3 parts, alternating with the milk. Start and end with the flour mixture. Mix just until combined.
7. Pour batter into the prepared pan and smooth the top.
8. Bake for 35–40 minutes, or until a toothpick inserted in the center comes out clean.
9. Let the cake cool completely in the pan before frosting.

Step 2: Make the Buttercream Frosting

1. In a large bowl, beat the butter until creamy (about 2–3 minutes).
2. Gradually add powdered sugar, 1 cup at a time, beating on low until combined.
3. Add vanilla and salt.
4. Add heavy cream 1 tablespoon at a time until desired consistency is reached.
5. Whip for 3–4 more minutes until light and fluffy.

Step 3: Frost the Cake

• Once the cake is completely cool, spread the frosting evenly on top. Use the back of a spoon or spatula to create pretty swirls like in the photo.

Serving & Storage:

• Serve at room temperature.
• Store covered at room temp for 2 days or refrigerate for up to 5 days. Best eaten within 3 days for freshness.

Tips:

• Add sprinkles, coconut flakes, or toasted nuts on top for fun texture.
• Want chocolate? Add ¾ cup cocoa powder to the dry cake mix and reduce flour by ½ cup.