01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease with butter or oil.
02 - In a large bowl, whisk together ricotta cheese, whole milk, vegetable oil, eggs, vanilla extract, lemon zest, and lemon juice until smooth and well blended.
03 - In a separate medium bowl, combine the all-purpose flour, granulated sugar, baking powder, baking soda, and salt. Stir to distribute evenly.
04 - Add the dry ingredient mixture to the wet ingredients. Stir gently with a spatula until just combined, being careful not to overmix.
05 - Gently fold the raspberries into the batter with a spatula, taking care not to crush them.
06 - Divide the batter evenly among the prepared muffin cups. Sprinkle the tops with coarse sugar for a crunchy finish, if desired.
07 - Bake for 20 to 24 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
08 - Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.