Preheat the oven to 180C/350F and grease and line a 2lb loaf tin.

Place the flour, baking powder, ground cinnamon and chocolate chips into a large bowl and stir together until the chocolate chips are coated in flour.

Place the butter and sugars into a large bowl or the bowl of your stand mixer and beat until light and fluffy, about 2 minutes on med-high speed.

Add in the eggs and vanilla extract and mix until well incorporated, about 1 minute on med-high speed.

Add in the flour mix and sour cream and mix on low until just combined, then turn the speed up to medium for 30 seconds to ensure everything is well mixed and smooth.

Pour the batter into your prepared loaf tin and level off with a spatula/wooden spoon.

Place in the oven for 60-75 minutes, until risen, golden and an inserted skewer into the centre comes out clean**.

Leave to cool in the tin for at least 1 hour before trying to remove. Transfer to a wire rack to cool completely.

Once cooled, slice into 10-12 pieces and store in an airtight container, at room temperature for 4 days.