Preheat your oven to 350 degrees Fahrenheit. Rub the sweet potato halves with coconut oil and place them cut-side down on a parchment-covered sheet pan. Roast for 25-30 minutes or until soft.
Scoop out the flesh of the sweet potatoes into a large bowl. Add the butter and mash the sweet potatoes until the butter melts. Add the milk, maple syrup, vanilla extract and cinnamon. Allow the sweet potato mixture to cool for about 5 minutes before mixing in the egg.
In another bowl, combine the almond flour, tapioca starch, rolled oats, and coconut sugar. Add the chunks of butter and work the butter into the mixture with the back of a fork until a crumbly mixture forms. Add int eh pecans and milk and work the crumble with the fork again until combined.