• 120 g unsalted butter (at room temperature)
• 200 g brown sugar
• 2 large eggs 
• 120 ml milk 
• ½ teaspoon pure vanilla extract 
• 120 g plain flour
• 60 g oat flour (or use 180 grams plain flour if substituting)
• 1 teaspoon baking powder 
• ¼ teaspoon salt 
• ½ teaspoon ground cinnamon 

Apple topping

• 120 g unsalted butter
• 150 g brown sugar
• ½ teaspoon ground cinnamon 
• ½ teaspoon pure vanilla extract 
• 2 large Cosmic Crisp® apples

1. Preheat the oven to 160°C (fan 140°C) and generously grease a 23 cm round cake tin.
2. Peel and thinly slice the apples.
3. Heat the butter and brown sugar in a small saucepan over medium heat and bring to a gentle boil. Cook until the sugar dissolves and the mixture thickens slightly, about 5-10 minutes. Remove from the heat and stir in the cinnamon and vanilla. Pour the mixture into the prepared cake tin and arrange the apple slices on top of the sugar mixture.
4. Sift together the flour, baking powder, salt and cinnamon in a medium bowl.
5. In a mixer, beat the butter and sugar together until creamy. Add the eggs one at a time, beating well after each addition and scraping down the sides of the bowl as needed.
6. With the mixer on low speed, slowly add the milk, followed by the dry ingredients. Mix just until incorporated, being careful not to overmix.
7. Pour the cake batter over the apples and bake for 40-45 minutes, until the cake is golden brown and the centre springs back when touched.
8. Allow the cake to cool in the tin for 10 minutes. Run a knife around the edges of the tin to loosen the cake, then invert it onto a plate. Tap the bottom of the cake tin before removing it and scrape out any remaining syrup onto the cake. Let the cake cool completely.