How to Make It
Prepare the Cornbread: Preheat oven to 425°F. Grease a 10-inch cast-iron skillet with butter. Place almond flour, flax meal, baking powder, and salt in a food processor. Gradually pulse in buttermilk and eggs until well combined, about 10 times. Transfer to prepared skillet.
Bake in preheated oven until browned and a wooden pick inserted in center comes out clean, about 15 minutes. Let cool completely, about 1 hour. Cut into 1-inch cubes.
While Cornbread cools, prepare the Stuffing: Reduce oven temperature to 350°F. Coat a 1 1/2-quart baking dish with cooking spray. Cook bacon in a large nonstick skillet over medium-high, stirring often, until browned, about 10 minutes. Transfer to a plate lined with paper towels. Add butter to drippings in skillet; melt over medium-high. Stir in onion and celery; cook, stirring often, until softened, about 8 minutes. Stir in pecans and sage; cook, stirring occasionally, 2 minutes. Remove from heat.
Stir together onion mixture, cooked bacon, cubed cornbread, broth, egg yolks, salt, and pepper in a large bowl. Transfer to prepared baking dish. Let stand at room temperature 20 minutes.
Bake at 350°F until mixture is set and top is golden brown, about 45 minutes, covering with aluminum foil during the final 15 minutes of cooking to prevent excessive browning, if necessary.