Preheat oven to 400°F. Line a 12-cup muffin tin with culinary paper liners.
Make the Roasted Pear Sauce first. Line a baking sheet with parchment paper, or grease or spray it lightly. Remove the core and stem from two Bosc pears (or other firm pears of your choice.) Brush with a little olive oil or coconut oil on both sides. Place cut side up on baking sheet. Transfer to oven and roast for 15 minutes.
Remove from oven, flip the pears over and roast with the cut side down for a further 10 - 15 minutes or until you can easily pierce with a fork. Remove from the oven and reduce oven temperature to 375°F. (to be ready to bake the muffins.) Purée the pears in a blender. Set the pear sauce aside to cool.
Mix topping ingredients together in a small bowl. Set aside.
In a medium bowl, whisk dry ingredients: oat flour, chai spices, baking soda, and sea salt.
Peel and finely dice the third pear. Add to the dry ingredients and toss to coat.
In a large bowl, whisk eggs, milk, maple syrup, melted coconut oil (or butter), vanilla extract and pear sauce.
Make a well in the center of the dry ingredients. Add the wet ingredients to the dry and gently stir to barely combine (about 10 to 12 strokes.) Do not overmix or muffins may be gummy. Batter will be lumpy and there may be a few spots where the flour is not completely mixed in.
Divide the batter evenly into 12 muffin cups. Top with a teaspoon or so of the topping mixture.
Bake at 375°F. for 15 - 18 minutes or until toothpick inserted comes out clean.
Remove from oven, let cool for 5 minutes, then transfer to cooling rack. Remove paper liners to prevent muffins from becoming soggy.
Once the muffins are completely cool, store in an airtight container for 3 days or in the freezer for up to 3 months.
If you don't want to make the Chai Spice Mix, add ½ tsp ground cardamom, ½ tsp ground allspice, 1 tsp cinnamon, ½ tsp ground cloves, and 1 ½tsp ground ginger to the dry ingredients instead of 4 tsp Chai Spice Mix.