Adjust oven rack to middle position. Preheat oven to 350 degrees F. Line the cups of a muffin tin with 12 paper liners. Set aside. Combine flour, sugar, baking powder, baking soda, and salt in a mixing bowl. Stir well; set aside. Using metal blade, process cream cheese, lemon juice, and vanilla in food processor until smooth. Add eggs and process 15 seconds. Scrape down side of container with a spatula. With processor running, pour hot melted butter through food chute within 10 seconds. Process another 10 seconds. Add milk and process 5 seconds. Add dry ingredients to container and mix with 4 to 6 half-second pulses. Add blueberries and mix until all are incorporated into batter, usually with 3 or 4 half-second pulses. (Or use a spoon to fold them in, if you prefer your berries whole.) Pour an equal amount of batter into each muffin cup, filling each about 3/4 full. Bake 30 minutes. Cool on rack 15 minutes. Makes 12 muffins. Recipe By : "The Food Processor", San Francisco Chronicle