Homemade Sponge Cake in a Blender (Makes a lot)

Ingredients:
• 5 eggs
• 65g butter (at room temperature)
• 450ml milk (at room temperature)
• 306g white sugar
• 150ml oil
• 1 tbsp vanilla extract •
350g all-purpose flour (0000)
• 70g cornstarch
• 15g baking powder