Preheat the oven to 350°F.
Spray a 9x13-inch baking pan with nonstick cooking spray.
In a large mixing bowl, combine the almond flour and baking powder.
Add salt, if using.
Add the beaten eggs, melted butter, water, and heavy cream.
Mix until the ingredients are fully combined and a smooth batter forms.
Pour the batter into the prepared baking pan.
Spread the batter evenly.
Bake for 15 to 20 minutes, or until a knife inserted into the center comes out clean.
Remove the cornbread from the oven.
Allow it to cool completely before preparing the stuffing.
Spray a second 9x13-inch baking pan with nonstick cooking spray.
Preheat the oven to 350°F.
Crumble the cooled cornbread into a large mixing bowl.
In a skillet over medium heat, melt the butter.
Add the chopped onion and celery.
Sauté until the vegetables begin to soften and lightly brown.
Pour 1/2 c chicken bone broth into the skillet.
Continue cooking until the vegetables are tender and the broth has mostly reduced.
Remove the onion and celery from the skillet and set aside.
Add 1 tbsp butter to the same skillet, if needed.
Add the sage leaves.
Cook for 20 to 30 seconds, just until fragrant.
Remove the sage from the skillet.
In a small bowl, beat the eggs until smooth.
Add the cooked sage to the beaten eggs.
Pour the egg and sage mixture over the crumbled cornbread.
Gently toss to combine.
Add the sautéed onion and celery.
Stir until evenly distributed.
Slowly add 1 c chicken bone broth, stirring after each addition.
Add the poultry seasoning.
Season with salt and black pepper, if desired.
Continue mixing until the stuffing is moist but not overly wet.
Transfer the stuffing mixture to the prepared baking pan.
Spread it evenly.
Bake at 375°F for 20 minutes, or until the top is lightly browned and the stuffing is set.
Remove from the oven.
Allow the stuffing to rest for several minutes before serving.
Serve warm.