1.In a large bowl, combine oats and milk. Let sit 15 minutes.
2.In a medium bowl, whisk flour, baking soda, baking powder, salt, and cardamom.
3.Preheat oven to 400°F. Lightly spray a muffin tin with oil. Set aside.
4.Stir the oil, egg, dark brown sugar and vanilla into the soaked oat mixture. Add dry ingredients. Stir just until combined. Gently fold pears into the batter.
5.Spoon the batter evenly into the prepared muffin tin. Stir the butter and brown sugar in a small bowl until the brown sugar dissolves. Top the muffin batter evenly with the mixture.
6.Bake 12 minutes then remove from the oven when a toothpick comes out clean. Let the muffins cool in the pan for 5 minutes then transfer to a cooling rack. Enjoy these muffins warm or freeze for later.