Cook the Sausage: Heat a large skillet over medium-high heat. Add the breakfast sausage and cook for 7–9 minutes, breaking it into small crumbles with a wooden spoon or spatula.

Continue cooking until no pink remains and the sausage reaches an internal temperature of 160°F (71°C) for pork sausage or 165°F (74°C) for poultry sausage.

Drain off excess grease and let the sausage cool for about 5 minutes.

Prepare the Baking Dish: Coat the inside of a 9 × 13-inch baking dish with the softened butter.

Cut each cooled pancake into quarters: Arrange approximately half of the pancake pieces across the bottom of the dish, overlapping them slightly where needed.

Add the Sausage Layer: Scatter half of the cooked sausage evenly over the first pancake layer.

Arrange the remaining pancake pieces over the sausage, then finish with the remaining sausage.

Keep the layers relatively even so each serving gets a similar amount of pancake and meat.

Make the Maple Egg Custard: In a large mixing bowl, whisk the eggs until the yolks and whites are fully combined.

Add the whole milk, heavy cream, ⅓ cup (80 mL) maple syrup, brown sugar, vanilla extract, cinnamon, nutmeg, and kosher salt.

Whisk until the sugar has mostly dissolved and the mixture looks uniform.

Add the Custard: Slowly pour the egg mixture evenly over the pancake and sausage layers.

Press the top pancake pieces gently into the liquid with a spatula so they begin absorbing the custard.

Do not mash the layers together; the goal is simply to moisten the exposed pancake surfaces.

Refrigerate Overnight: Cover the baking dish tightly with aluminum foil. Refrigerate for at least 8 hours and up to 12 hours.

During this time, the pancakes will absorb much of the custard. The casserole should look moist but not flooded with liquid when you check it the next morning.

Prepare for Baking: Remove the casserole from the refrigerator and let it stand at room temperature for 10 minutes while the oven preheats.

Preheat the oven to 350°F (175°C). Keep the baking dish covered with foil during the initial baking stage.

Bake Covered: Place the casserole on the center oven rack.

Bake, covered, for 30 minutes. The edges should begin to set, while the center may still look slightly soft.

Finish Baking Uncovered: Carefully remove the foil: Continue baking for another 15–20 minutes, until the top is lightly golden and the center looks set rather than liquid.

The casserole should reach at least 160°F (71°C) in the center because it contains eggs. If the middle is still loose, continue baking in 5-minute increments.

Rest Before Serving: Remove the casserole from the oven and let it rest for 10 minutes.

The custard will continue to set slightly as it cools, making the casserole easier to cut into neat portions.

Garnish and Serve: Cut the casserole into 8 portions. If desired, dust lightly with powdered sugar and drizzle with the optional maple syrup just before serving.

Serve warm.