School Cake
A nostalgic, soft, fluffy yellow sheet cake topped with simple white icing and colourful sprinkles. This timeless classic (inspired by Jane's Patisserie) is ridiculously easy but delivers big on simple, happy flavour, bringing back childhood memories. Perfect for sharing and creating new joyful moments.
Equipment
- 9x13 inch Traybake Tin
- Parchment paper
- Electric Mixer (Handheld or Stand)
- Large mixing bowl
- Medium Mixing Bowl (for icing)
- Measuring Cups & Spoons
- Spatula
- Sifter
- Wire Cooling Rack
- Offset Spatula or Spoon (for spreading batter/icing)
Ingredients
For the Cake:
- 400 g Unsalted Butter about 1 ¾ cups or 3.5 sticks, softened to room temperature
- 400 g Caster Sugar about 2 cups (Granulated sugar works too)
- 7-8 medium Eggs room temperature
- 400 g Self-Raising Flour about 3 ¼ cups (See Note for US alternative)
- 1 tsp Vanilla Extract
- 4 tbsp Milk room temperature (Whole milk recommended)
For the Icing:
- 500 g Icing Sugar Powdered Sugar (about 4 cups), sifted
- 4-5 tbsp Water adjust as needed
- Rainbow Sprinkles generous amount!
Instructions
- Preheat oven to 180°C / 350°F (160°C fan). Grease and line a 9x13 inch traybake tin with parchment paper, leaving an overhang.
- In a large bowl, beat the softened butter and caster sugar with an electric mixer for 3-5 minutes until pale, light, and fluffy.
- Add the eggs one at a time, beating well after each addition. Scrape down the bowl sides occasionally. Beat in the vanilla extract with the last egg.
- Add the self-raising flour. Mix on low speed or fold gently with a spatula just until almost combined (do not overmix).
- Add the milk and mix again gently on low speed or by hand only until the batter is smooth and just combined, with no flour streaks remaining.
- Pour batter into the prepared tin and spread evenly.
- Bake for 45-50 minutes, or until golden brown, springs back when gently pressed, and a skewer inserted into the center comes out clean. Start checking around 40 minutes.
- Leave the cake to cool completely in the tin on a wire rack.
- Once completely cool, make the icing: Sift icing sugar into a medium bowl. Add water 1 tablespoon at a time, mixing well, until a thick, smooth, spreadable paste forms.
- Pour or spoon the icing onto the center of the cooled cake and spread evenly over the top.
- Immediately cover generously with rainbow sprinkles while the icing is still wet.
- Let the icing set for at least 1 hour before slicing into squares and serving.
Notes
US Flour Substitute: If you can't find self-raising flour, use 3 ¼ cups All-Purpose Flour PLUS 5 teaspoons Baking Powder and ¾ teaspoon Salt, whisked together well before adding. Tips for Moisture: Don't overbake! Use room temperature butter, eggs, and milk. Real butter and whole milk yield the richest result. Storage: Store leftover cake in an airtight container at room temperature for 3-4 days. Troubleshooting: Dense cake often means overmixing after adding flour. Dry cake usually means overbaking. Ensure tin is well-greased and lined to prevent sticking. Alternative Tin: For a 9" square tin, the original source suggests a 5-egg mix (250g butter, sugar, self-raising flour; 5 eggs; ~3 tbsp milk; 1 tsp vanilla) baked for ~35 mins.
