Easy Cake Batter Blondies

Bahan-bahan (20 porsi)

• 1 13.25 -ounce box yellow or vanilla cake mix (just the DRY mix)*
• 1/4 cup (60ml) vegetable oil
• 1 large egg, at room temperature
• 6 Tablespoons (90ml) whole milk, at room temperature
• 1/2 cup (85g) rainbow sprinkles, plus extra for topping if desired
• 1/2 cup (90g) white chocolate chips