Preheat oven to 450F (regular bake setting/not convection bake).
Combine all the pancake batter ingredients in a blender and blend to combine. Leave in the blender and allow to stand 20-30 minutes.
If starting with uncooked breakfast sausage, cook the sausage in a skillet over medium heat with a little oil until golden brown or see Note 1 below for how to cook them in the preheating oven. Set aside.
When ready to cook, put the empty skillet into the oven for 5 minutes. Re-blend the batter briefly and have it handy next to the oven. Also, have your fully-cooked sausage and blueberries at the ready. Remove from oven (careful, it's hot!). Add the 1 Tablespoon of butter to the hot pan and allow to melt, then pour the batter into the pan. Arrange the sausage around the pan and scatter the blueberries over top.
Place into the preheated oven and bake, undisturbed, for 22-25 minutes, or until puffed and golden.
Remove from oven and let stand a minute or two. Dust with icing/confectioners' sugar and drizzle with maple syrup to serve.
Notes
1. Use either store-bought, fully-cooked breakfast sausages OR pre-cook the sausages yourself. You can do this well ahead and refrigerate if you like. You can also make use of the preheating oven to cook the sausages right before making them if you like. Simply throw them in the skillet and into the preheating oven, cooking until they are cooked through and golden. Remove any excess fat from the pan, leaving a bit in the pan to replace the butter for the pan. You can pour the batter over top of the sausages in the pan.Be sure to read the notes above the Recipe Card for substitution suggestions and tips for making this recipe. You will also find Step-by-Step photos for reference.