Preheat the oven to 400°F. I like to melt the butter in a small saucepan over the stovetop for the batter first, but you can also do it in the microwave if you prefer.
To make the batter: Add the flour, cane sugar, baking powder, cornstarch, nutmeg, cinnamon, and sea salt to a large mixing bowl.
Whisk together to combine the flour mixture completely.
Next add the wet ingredients: egg, sparkling apple cider, heavy whipping cream, yogurt, melted butter, and vanilla extract.
Mix together using a hand mixer, spatula or even just a whisk until you have a smooth batter. Transfer the batter to a piping bag.
Spray the donut pans with avocado oil cooking spray. Pipe the batter into the pans, or if you don’t want to pipe, you can also just spoon it into the pans too!
Bake for 10 to 14 minutes, or until they are golden brown or a toothpick inserted comes out clean. Allow to cool completely in the pans.
To make the topping: In a medium bowl, add the cane sugar and cinnamon and mix together. Add the melted butter into a second bowl.
Dunk each donut into the melted butter, and then dip it into the cinnamon and sugar mixture to coat it completely as you want to have cinnamon and sugar in every bite of each donut!