01 - Preheat oven to 375°F (190°C). Line a standard 12-cup muffin tin with paper liners or grease each cup thoroughly.
02 - In a large mixing bowl, combine the all-purpose flour, baking powder, baking soda, salt, and ground black pepper. Stir in the chopped dill and shredded cheddar cheese if desired.
03 - In a separate bowl, whisk together the eggs, olive oil or melted unsalted butter, whole milk or unsweetened plant-based milk, and pickle juice until fully blended.
04 - Add the mashed sweet potato and finely chopped dill pickles to the wet mixture, stirring until smooth.
05 - Pour the wet ingredients into the dry ingredients. Stir gently with a spatula until just combined, ensuring not to overmix the batter.
06 - Using a spoon or ice cream scoop, distribute the batter evenly among the muffin cups, filling each approximately three-quarters full.
07 - Place the muffin tin on the center rack of the oven and bake for 20 to 22 minutes, or until golden brown and a toothpick inserted into the center of a muffin comes out clean.
08 - Allow muffins to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.