Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper to prevent sticking.
In a medium bowl, whisk together the all-purpose flour, sugar, salt, baking powder, and baking soda until well combined.
In another bowl, whisk together the canola oil, egg, vanilla extract, and milk until smooth.
Pour the wet mixture into the dry ingredients. Stir gently until just combined. Be careful not to overmix; a few lumps are perfectly fine!
Gently fold in the melted Nutella until evenly distributed throughout the batter.
Using an ice cream scoop or a spoon, drop small portions of the batter onto the prepared baking sheet, spacing them about 2 inches apart.
Bake the donut holes in the preheated oven for 10-12 minutes, or until they are lightly golden and a toothpick inserted into the center comes out clean.
While the donut holes are baking, combine the granulated sugar and ground cinnamon in a small bowl.
Once the donut holes are baked, remove them from the oven and let them cool slightly on a cooling rack. While they are still warm, brush them with melted butter and roll them in the cinnamon sugar mixture until fully coated.
Serve the Nutella Churro Donut Holes warm and watch them disappear in no time!
