Preheat oven to 350 °F
Chop the Rhubarb and put them in a microwave-safe bowl.
Sprinkle 3 tbsp of the Splenda sweetener over the rhubarb and stir it to cover.
Microwave the rhubarb for about 2 minutes at 30 second intervals, stirring in between and then set aside.
Sift the King Arthur Flour, baking powder, and baking soda into a mixing bowl.
In a separate mixing bowl, cream the butter until smooth.
Add the egg and beat well.
Add the milk, followed by the sweetener and mix well.
Add the Rhubarb compote and mix in.
Slowly mix in the dry ingredients on low speed, a scoop or two at a time.
If you find the batter getting too dry, add a little extra milk or a tablespoon of water.
Once mixed into a smooth batter, fold in the chopped rhubarb.
Divide the batter between 12 muffin cups, lined with paper or silicone muffin liners.
Bake in the oven for 18-22 minutes or until a toothpick, when inserted into the cupcake comes, out clean.
Remove from the oven and place them muffins on a wire baking rack to cool.