Blueberry Lemon Cupcakes

Ingredients

• 3 tsp baking powder
• 2 large eggs
• 1/2 tsp fine salt
• 1/2 cup vegetable oil
• 1 tbsp blueberry jam
• 3 1/2 cups all-purpose flour
• 2 lemons zested
• 1/2 cup unsalted butter (softened)
• 1 batch cream cheese frosting
• 2 tbsp Greek yoghurt (or sour cream)
• 2 cups frozen blueberries
• 1 tsp vanilla extract (vanilla bean paste)
• 1 1/4 cups caster sugar (superfine)
• 1 1/2 cups whole milk (full-cream)
• 2 batches of my cream cheese frosting
• 1 tsp lemon essence (optional)