Moist lemon sponge cake

Ingredients

• 3 eggs
• 1/2 cup sugar
• 1/2 cup all purpose flour
• 1/4 teaspoon baking powder
• 1/4 teaspoon salt
• 1/4 cup melted unsalted butter
• 1/2 teaspoon vanilla extract
• 1 teaspoon lemon zest
• 2 teaspoons lemon juice