PREP: Preheat the oven to 350 degrees F. Spray 8 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 a separate 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 8 muffin cavities 3/4 full. All of the batter should be used among the 8 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; over- baking will make these muffins less moist 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.