Mix the whole-wheat pastry flour, baking powder, baking soda, sugar, and salt in a bowl.
Puree the strawberries in a blender along with the nondairy milk. Place in a bowl. (You can sub half the strawberry puree with an equal amount of applesauce for some added sweetness and moistness).
Add the flaxmeal and vanilla extract and mix well.
Make a well in the flour and pour in the wet ingredients. Using just a few strokes of your ladle or whisk, mix until everything's just moistened. Don't overbeat-- a few lumps are just fine. Just make sure you don't have any visible dry flour. If the batter is too dry, add a little more nondairy milk and mix it in.
Add the blueberries and mix in.
Pour the batter in a muffin tin lined with paper liners. If you don't have paper liners spray with oil, although I do recommend the paper liners so you can get your muffins out more easily.
Sprinkle some sugar over the top of each muffin. This is not a very sweet muffin, so I like the little added crunch and sweetness on top.
Bake the muffins in a preheated 400-degree oven for 15 minutes or until a toothpick inserted in the center comes out clean.
Cool the muffins on a rack for about 10 minutes, then slide the muffins out of the tin and continue cooling on the rack.
Nutrition estimate per muffin: Calories 112, Total Fat 0.5 grams, Potassium 103.5 mg, Dietary Fiber 2.4 grams, Sugar 3.2 grams, Protein 2.5 grams