Chocolate sheet cake for 30 kids bakes in one 12 by 16 inch (30 by 40 cm) oven pan and cuts into 30 equal squares. It suits a birthday party at kindergarten or school, because the batter is made in one bowl with no mixer and no eggs.

How to get 30 squares

Line the big pan with baking paper and pour the batter straight in. After cooling, cut 5 pieces across and 6 along the length. Each square is about 2 1/2 by 2 3/4 inches (6 by 7 cm), a comfortable size for a child's hand.

The glaze is a simple chocolate ganache of dark chocolate and heavy cream. Colorful sprinkles are optional and go on while the glaze is still soft.

Why the batter has no eggs

Baking soda and vinegar react and form bubbles that lift the cake, so no eggs are needed. That also solves a common problem at children's parties, since eggs are one of the most common allergens. Add the vinegar last and pour into the pan at once, so the bubbles stay in the batter. The cake itself is dairy-free, and the dairy sits only in the glaze. If a child in the class is sensitive to dairy, skip the glaze and dust with powdered sugar.

Bake Thursday, serve Friday

If the party is on Friday, bake the cake on Thursday evening. Cover the pan with foil and carry the cake to the party in the pan itself, then cut it there, so it does not break on the way.

Chocolate Sheet Cake for 30 Kids

An eggless chocolate cake baked in one 12 by 16 inch sheet pan and cut into 30 squares.

Chocolate Sheet Cake for 30 Kids
Servings: 30 squaresPrep time: 20 minCook time: 35 minTotal time: 55 min

Ingredients

For the cake

  • 4 1/2 cups / 560 g all-purpose flour
  • 2 1/2 cups / 500 g sugar
  • 3/4 cup / 65 g unsweetened cocoa powder
  • 3 tsp baking soda
  • 1 1/2 tsp salt
  • 1 cup / 240 ml vegetable oil
  • 3 tbsp white vinegar
  • 1 tbsp vanilla extract
  • 3 cups / 720 ml water

For the glaze

  • 7 oz / 200 g dark chocolate (chopped)
  • 3/4 cup + 1 tbsp / 200 ml heavy cream

To finish (optional)

  • colorful sprinkles

Instructions

  1. Heat the oven to 350°F / 180°C. Line a 12 by 16 inch / 30 by 40 cm oven pan with baking paper.

  2. In a large bowl, stir together the flour, sugar, cocoa, baking soda and salt.

  3. Add the water, oil and vanilla and whisk until the batter is smooth.

  4. Add the vinegar, stir for 10 seconds and pour into the pan right away.

  5. Bake 30 to 35 minutes, until a toothpick in the center comes out dry. Cool completely.

  6. Heat the cream to just below a boil and pour it over the chopped chocolate. Wait 1 minute, then stir until smooth.

  7. Spread the ganache over the cooled cake and add sprinkles if you like. Cut into 5 by 6 squares.

Frequently Asked Questions

How do I store the cake until the party?
In the pan, covered with foil, at room temperature, for up to two days.

Should I cut it before or at the party?
At the party, since cut squares dry out at the edges on the way.

Can I use a smaller pan?
Yes, halve the amounts and bake in an 8 by 12 inch (20 by 30 cm) pan, which gives about 15 squares.

Can I make the glaze ahead?
Yes, the ganache keeps in the fridge for up to two days. Warm it slightly before spreading.