Prepare the Tin and Oven: Preheat your oven to 180°C (160°C Fan). Grease and line a 900g (2lb) loaf tin with parchment paper, leaving some overhang to help you lift the loaf out later.

Mix the Dry Ingredients: In a medium bowl, whisk together the plain flour, baking powder, and salt. Set it aside for later.

Make the Cinnamon Swirl: In a separate small bowl, combine the 50g of light brown soft sugar and 2 teaspoons of ground cinnamon for the filling. Mix well and set aside.

Cream Butter and Sugars: In a large bowl using a stand mixer or an electric hand mixer, beat the softened 115g of unsalted butter with the caster sugar and 50g of light brown sugar. Beat on medium-high speed for about 3-4 minutes until the mixture is light, pale, and fluffy. This step, known as the creaming method, incorporates air for a lighter cake.

Add Eggs and Vanilla: Add the eggs one at a time, beating well after each addition until fully incorporated. Scrape down the sides of the bowl as needed. Mix in the vanilla bean paste.

Combine Wet and Dry: Reduce the mixer speed to low. Add the flour mixture in three additions, alternating with the soured cream in two additions. Begin and end with the flour mixture (Flour -> Soured Cream -> Flour -> Soured Cream -> Flour). Mix only until just combined – a few small streaks of flour are fine. Over-mixing will make the bread tough.

Layer and Swirl: Spoon half of the batter into your prepared loaf tin and spread it out evenly. Sprinkle the cinnamon-sugar swirl mixture evenly over the top. Add the remaining batter on top and smooth it out. To create the swirl, I find that inserting a butter knife and making a gentle "S" shape or figure-of-eight motion just twice through the batter works best. Don't overdo it, or you'll lose the distinct ribbon.

Bake the Loaf: Bake for 50-60 minutes, or until the top is golden brown and a skewer inserted into the centre comes out clean. If the top starts to brown too quickly, you can loosely cover it with foil for the last 10-15 minutes.

Cool and Top: Let the loaf cool in the tin for 15 minutes before using the parchment paper overhang to lift it onto a wire rack to cool completely. While it's still slightly warm, prepare the topping. Mix the granulated sugar and 1 teaspoon of cinnamon in a shallow dish. Brush the top and sides of the loaf with the 60g of melted butter, then generously sprinkle the cinnamon sugar all over, pressing gently to help it adhere. For a treat that leans more towards breakfast, you might also like these Maple Pecan Sticky Buns.