In a small saucepan, mix cornstarch with a small amount of the water until smooth.
Add remaining water, blueberries, and honey. Stir over medium heat until thickened and translucent.
Remove from heat; stir in lemon juice.
In a medium bowl, mix together flour, baking powder, brown sugar, and salt.
In a small bowl, use a fork to mix egg, milk, and oil.
Add wet ingredients to dry ingredients and stir only enough to moisten (batter should be slightly lumpy). If desired, stir in peaches.
For each pancake, pour about 1/4 c. batter into a preheated lightly oiled or nonstick-sprayed frying pan. Cook until bubbles appear and edges are slightly dry. Flip pancakes and brown the other sides.
Serve warm blueberry sauce over pancakes.