Preheat oven to 375 degrees F. Line 2 baking sheets with silicone liners or parchment paper. Set aside.

In a large bowl, combine the muffin mix - just the dry mix, oats, oil, brown sugar, egg and milk and stir together until a soft dough just barely comes together. Drain and rinse the canned blueberries; gently fold into the dough to combine.

Portion rounded, heaping Tablespoonfuls of dough onto the prepared baking sheets. Bake for approx. 8-10 minutes, rotating pans halfway through baking time to ensure even cooking. Cool on the sheets completely.

Meanwhile, make your glaze. Combine all the glaze ingredients except for the milk together in a bowl, only using milk if needed, until smooth and pourable. Glaze the tops of the cookies and let set, about 10 minutes. Then serve!