Preheat oven to 350F. Add all the dry ingredients to a bowl and whisk to combine.
In a separate bowl, add in the eggs, sour cream, heavy cream, swerve, brown swerve and vanilla, then mix to combine. Add in the dry ingredients and mix, just until combined.
Scoop into 10 silicone cupcake liners or paper liners. Bake for 18-20 minutes or until a toothpick, when inserted, comes out clean. Allow the cupcakes to cool before frosting.
To Make the Frosting
Add all of the ingredients to a mixing bowl and reserve a little heavy cream. Mix using a hand mixer, until well combined.
Scrape down the sides and add in the remaining heavy cream, if needed. Continue mixing until smooth and creamy. Transfer to a piping bag fitted with the tip of your choice.
If you don't have a piping bag, you can use a plastic food storage bag. If you don't have a decorating tip, you can cut a hole at the tip of the bag and swirl the frosting over the top.
You can certainly substitute with vanilla extract, but you won’t get the same intense vanilla flavor or the flecks of vanilla beans throughout. The Oat Fiber is really important in this recipe. I use it in so many recipes, because of the amazing texture it gives whatever I am baking! It is hands down, the best ingredient I’ve baked with and is really worth buying. I use Lifesource Foods Oat Fiber 500 and I buy it in the 16 ounce bag on Amazon (link in recipe). The bag lasts a while because you don’t need to use much in your recipes. Oat Fiber, is not the same as Oat Flour, which is made from grinding oats. Oat Fiber is made from grinding the outside husks of oats and is pure insoluble fiber. Insoluble fibers do not dissolve in water and are not broken down in the digestive tract.