Preheat oven to 400 degrees F (205 C). Grease a standard-size muffin tin with a light layer of neutral oil or butter and reserve to the side.
In a large mixing bowl, combine the flour, baking powder, baking soda, salt, cinnamon, cardamom, and nutmeg until evenly dispersed. Then add the diced pears, tossing lightly to coat. Reserve to the side.
In a medium mixing bowl, combine the sourdough discard with the melted butter, stirring with a whisk or fork until combined. Then add the egg and vanilla, stirring to combine.
Add the brown sugar and granulated sugar to the wet ingredients, mixing well to combine evenly.
Add the wet ingredients to the dry ingredients, gently folding in with a wooden spoon or rubber spatula until just combined with no large dry patches; some lumps are okay. Do not overmix.
Spoon prepared batter into the reserved muffin tin, dividing evenly among the 12 cups.
Sprinkle the tops of each muffin cup with a bit of turbinado sugar.
Bake for 18 minutes, or until a toothpick inserted in the center of the muffins comes out clean.
