I once saw a recipe for a "sausage cake" in a very old community cookbook. That recipe turned out to be a disaster, but the idea intrigued me so, I kept trying and created this version. This is best served shortly after baking, though it’s fine at room temperature. If you want quick prep for breakfast, cook the sausage and onions and toss with the sage and cheese the night before, cover and refrigerate. Add the egg, make the batter and bake in the morning. - TheRunawaySpoon
Don't wait for a special occasion to make this breakfast cake. It is amazingly easy to make, bakes up quickly, and most importantly, tastes great. Warm from the oven, the sausage and melted cheese mingle together in a soft cake that is reminiscent of a biscuit. Left-overs also warm up beautifully, making this a perfect savory companion to a cup of coffee any morning. Note: I added 1/2 tsp of salt to the batter as my sausage wasn't too salty. —monkeymom
Preheat the oven to 400 degrees. Grease an 8 by 8 inch baking dish.
Break the sausage into pieces and place in a skillet. Cook the sausage until it is beginning to brown and has rendered some of its fat, breaking it into small pieces as you cook. Add the onion and continue to cook until the sausage is browned and no longer pink in the middle and the onions are soft. Drain well and leave to cool slightly.
Place the cooled sausage and onion into a bowl and add the cheddar cheese and sage. Toss to combine. Add the lightly beaten egg and stir to mix everything together well.
In another bowl, stir the flour, baking powder and baking soda together with a fork. Add the milk and mayonnaise and stir with the fork to combine. Pour 1/2 of the batter into the prepared pan and spread to cover the bottom. Spread the sausage and cheese mixture evenly over the batter in the pan, then spread the remaining batter over the top. Do the best you can, but it will not cover the top of the sausage mixture and that’s fine.
Bake the cake for 20 – 25 minutes until firm and golden. Serve warm.