Preheat oven to 400°F. Line 12 muffin cups with paper liners; lightly spray liners with cooking spray.
Into a bowl, sift together flour, baking powder, and salt.
In a bowl using an electric mixer, beat vegetable oil spread on medium speed until creamy. Gradually add Splenda Sweetener, beating until light and fluffy.
Add eggs one at a time, mixing well after each addition. Mix in vanilla extract.
Add half of flour mixture, blending to combine. Add milk and mix to combine, then add remaining flour and mix on low speed. Fold in blueberries.
Spoon batter evenly into prepared muffin cups. Bake for 20–22 minutes or until golden. Remove from pan immediately and cool on a wire rack.