Preheat the oven. Line the muffin tin with the molds. Peel, quarter, core and roughly grate the pears (or apples). Mix the flour and baking powder.
Whisk the sugar with sour cream, butter and salt. Stir in the eggs. Quickly stir in the flour mixture and grated pear.
Pour the batter into the molds. Bake in the oven at 180 degrees (center, fan 160) for 10 minutes. Pull the grid and the tray out of the oven a little, sprinkle the popcorn on the muffins, press down gently. Bake ready in 10-15 minutes. Let rest for 5 minutes, take out and let cool down.