I always start by preheating my oven to 350°F and lining my muffin pan with paper liners. If I do not have liners on hand, a light coat of oil works just as well. Getting this step done first means the batter goes straight into the oven once it is ready.
Next, I peel, core, and dice my pear into very small cubes. This part matters more than you would think, because large pear chunks tend to sink to the bottom of the muffins before they finish baking. Small, even pieces distribute much better through the batter.
In a large bowl, I whisk the eggs and brown sugar together for a minute or two until the mixture turns slightly foamy. Then I add the oil and Greek yogurt and whisk again until everything looks smooth and fully combined. This gives the batter its soft, moist base.
In a separate bowl, I combine the self-rising flour with the cinnamon, ginger, and allspice. Mixing the spices into the flour first, rather than adding them straight to the wet mix, helps them spread evenly through the batter instead of clumping in one spot.
I add the flour mixture into the wet ingredients and whisk just until no lumps remain. I try not to overmix here, since too much whisking makes the muffins dense instead of light. Once the batter is smooth, I gently fold in the diced pear with a spatula.
Using an ice cream scoop, I portion the batter evenly into the lined muffin pan. I like to save a few pear pieces to press onto the tops before baking, since it makes the finished muffins look even more appetizing.
I mix the demerara sugar and cinnamon in a small bowl and sprinkle a little over each muffin. This step is optional, but that crunchy sugar top is honestly my favorite part of the whole recipe.
I bake the muffins for about 20 minutes, until they are puffed, golden, and a toothpick comes out clean. Once they are done, I move them to a wire rack and let them cool completely before removing them from the pan.