Preheat oven to 325℉ and grease a 9" round cakepan with a bit of coconut oil.
Cream together the avocado oil, maple syrup and vanilla extract in a stand mixer with a paddle attachment, or using electric beaters until creamy. This will take about 5 minutes.
Add the eggs, egg whites and milk to the oil/syrup/vanilla, and mix until well combined and smooth.
In a separate, large mixing bowl, whisk all of the dry ingredients, including the sprinkles, together then add to the wet ingredients. Mix gently so you don't break the sprinkles.
Pour batter into prepared cake pan, and bake for 35-40 minutes until the edges are starting to look golden brown, and the center of the cake has a dome and is starting to crack a bit.
Let the cake cool for 20 minutes in the pan, then carefully transfer to a cooling rack to finish cooling. If you're planning to frost the cake, I recommend wrapping tight in parchment paper, then storing in the refrigerator in an airtight container for a few hours first.