PREP: Preheat the oven to 350 degrees F. Spray eight cavities of a light-colored muffin tin with nonstick cooking spray and fill the other empty cavities halfway with water (ensures even baking). Do not use muffin liners -- these muffins stick to the paper.
MUFFIN BATTER: In a large bowl, using a hand mixer, beat the applesauce, almond butter (See Note 1), honey, vanilla extract, and brown sugar (See Note 2) in a large bowl. Beat in the egg until mixed in. Add the salt, baking soda, baking powder, and oat flour (See Note 3). Mix. Stir in the old-fashioned oats and mix to combine.
APPLE: Peel the apple and chop into small pieces. In another small bowl, toss the chopped apple with the lemon juice. Add the apple pieces (and any accumulated liquid) to the muffin batter along with 2 tablespoons of chopped pecans and the ground cinnamon. Gently stir to combine.
BAKE: Fill the eight muffin cavities 3/4 full. All of the batter should be used among the eight cavities. Evenly sprinkle the last two tablespoons of pecans on the tops of the muffins. Bake at 350 degrees for 16-18 minutes or until lightly browned around the edges. Watch carefully; overbaking will make these muffins dry and less flavorful.
ENJOY: Let the muffins stand in the muffin tin for 5-10 minutes before gently coaxing them out, with a spoon, onto a cooling rack (while hot, these muffins have a tendency to crumble). Allow muffins to finish cooling on the cooling rack. Muffins are best enjoyed within 2-3 days. Store in an airtight container at room temperature. Muffins can be frozen for up to 2 months, individually and tightly wrapped in plastic wrap. Thaw at room temperature.