Mix dry ingredients. In a small bowl combine the sweet rice flour, baking powder and salt.
Mix wet ingredients. In the stand mixer bowl whisk the butter, brown sugar and egg until well incorporated. Add the vanilla extract, ube halaya jam, ube extract and coconut milk until well combined.
Combined dry and wet ingredients. Slowly pour half the dry ingredients and mix at low setting on the stand mixer. Gradually add the remaining half and mix. Do not over-mix the batter.
Preheat Oven. Preheat the oven to 350°F.
Grease the donut pan. Spray with a neutral oil spray in each of the donut cavities. Using a spatula scoop the batter into each of the donut cavities. Fill each one until it's 90% full and use the spatula to remove any air bubbles.
Bake. Bake on the middle rack for 12-13 minutes. Remove from oven and let it cool for 5 minutes before moving to a cooling rack.
Make the glaze. In a medium bowl whisk ¼ cup of confection sugar with 1 tbsp of whole milk and add the remaining ¼ cup of confection sugar. Add 1/2 tbsp of whole milk and whisk until it's smooth. Once the glaze is smooth consistency add the ube extract and whisk until well incorporated. The glaze should have the same consistency as glue.
Glaze donuts. Once the donuts have cooled dip the top of the donuts (This would be the side that was facing down in the donut baking pan) and flip it up. Place the glazed donuts back onto the cooling rack. Let the first coat of glaze harden slightly. I give it 5 minutes and dip the donuts once again to get a thicker layer of glaze.