Grease and line a 8.5 x 4.5 inch (21 x 11cm) loaf pan with parchment paper. Ensure it hangs over the sides of the tin for easy removal after baking. (See note 2)
Position the oven rack in the middle of the oven, and preheat to 356° F / 180° C (160° C fan)
Wet ingredients: In a large bowl, beat together the butter and white granulated sugar until just combined, then mix in the vegetable oil.
Continue beating until the mixture is light and pale in color, about 2 minutes on medium speed.
Add the one at a time, mixing well after each addition until fully combined before adding the next.
Dry ingredients: In a separate bowl, whisk together the all-purpose flour, baking powder, ground cinnamon and salt.
Combine mixtures: Gradually add the dry ingredients to the wet mixture, alternating with the sparkling apple cider. Start and end with the flour, mixing until just combined. Avoid overmixing.
Pour and bake: Pour the batter into the prepared loaf pan, smoothing the top. Bake for 45 - 50 minutes, or until a toothpick inserted in the center comes out clean. If the top of the cake is getting too dark during baking, you can tent it with foil without letting it touch the surface of the loaf.
Cool the loaf: Let the loaf cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.