In a mixing bowl, combine flour, Splenda, brown sugar, baking powder and salt. Mix well.
In a separate, large mixing bowl, combine soymilk, syrup, egg substitute, butter, applesauce and vanilla extract. Using an electric mixer or a whisk, mix until thoroughly blended. (Don't worry if butter bits do not break up completely.)
Add dry ingredients from the first mixing bowl to the mixture in the large one. Mix until completely blended. Then fold in the blueberries.
Line a 6-cup muffin pan (or half a 12-cup pan) with baking liners and/or spray with nonstick spray. Evenly distribute batter among the 6 cups.
Place in the oven and bake for about 22 minutes, until a toothpick inserted into the center of a muffin comes out clean. Enjoy!