Preheat oven to 350 degrees and grease an 8-inch baking dish with butter. Set aside.
Using the back of a fork or a whisk, mash the blueberries to release all their juices, and mix in the maple syrup, coconut sugar and lemon zest. Set aside.
In a medium bowl, whisk together the melted butter, almond extract, ginger and milk.
Then add the flour, baking powder and salt and continue whisking just until the batter is smooth. Transfer the batter (it’s not a lot—don’t worry!) to the greased baking dish, and spread evenly into corners.
Spoon the blueberries and all their juices over the top of the cake batter. Place in the oven and bake for ~20 minutes, or just when a toothpick comes out clean in the center.
Remove from the oven and allow to cool for a few minutes. Serve warm with ice cream (optional).