Easy Moist Butter Cake - Hungry Lankan

Ingredients

• 1 tbsp Butter
• 1 tbsp flour
• 250 g Granulated Sugar
• 225 g Unsalted Butter (room temp)
• 225 g Cake flour or all purpose flour
• 4 Eggs (room temp)
• 1 Egg yolk (room temp)
• 1/3 cup Milk (room temp)
• 2 tsp Pure vanilla extract (or 1tsp vanilla essence)
• 2 tsp Baking powder
• 1 pinch Salt