Healthy Apple Oat Muffins - Bake with Amy

Ingredients

• 200 g self-raising flour (1 1/4 cups)
• 125 g soft brown sugar(1/2 cup)
• 45 g rolled oats (1/4 cup for muffin filling, 1/4 cup for topping)
• 1 ½ tsp ground cinnamon
• 50 ml neutral vegetable oil
• 140 ml buttermilk, at room temperature
• 1 tsp vanilla extract
• 1 egg, at room temperature
• 1 ½ apples, peeled/cored and diced small (1 apple for the muffin filling, 1/2 apple for the topping)