Roast the purple sweet potatoes for 40-45 minutes or until it is soft enough for a fork to pierce through
Peel the potatoes then mash them in a bowl then measure them into a cup along with one cup of milk. Pour both into a blender and blend them until the mixture is smooth.
Pour the mixture from the blender into a bowl and add the remaining ¼ cup milk, egg, and 3 tablespoons melted butter.
In another bowl, combine 1 tablespoon sugar with ¼ teaspoon salt, 2 tablespoon cornstarch, ½ cup sweet rice flour, and ½ cup all-purpose flour. Add the dry ingredients to the wet ingredients, whisking just until combined.
Once the dry ingredients are mixed, add them to the wet ingredients and whisk them together until they're well combined or no remnants of dry ingredients are seen.
Heat a griddle over medium-low heat. Scoop about ⅓ cup batter per pancake and cook until both sides are browned.
Repeat the process with the rest of your mixture and serve the pancakes fresh.
Notes
If you want to cut the time that comes from cooking the sweet potato, you can also use ube halaya or ube jam as an alternative to adding ube flavoring. Experiment first with tablespoons of the flavoring to see what suits your taste.