Preheat oven to 400 °.
Press dough into bottom and up sides of a 10-inch removable-bottom tart pan. Line bottom of dough with a piece of foil; arrange pie weights or dried beans on foil. Bake at 400° for 5 minutes. Remove pie weights and foil. Bake an additional 5 minutes. Cool on a wire rack.
Combine rhubarb, 1/2 cup sugar, cornstarch, water, and 1/2 teaspoon cinnamon in a medium saucepan. Bring to a boil; reduce heat, and simmer 5 minutes or until rhubarb is tender, stirring frequently. Remove from heat, and stir in strawberries. Spoon strawberry mixture into prepared crust. Combine 1/4 teaspoon cinnamon and 1 tablespoon of sugar; sprinkle evenly over tart.
Place tart on a baking sheet. Bake at 400° for 30 minutes or until filling is set. Cool on a wire rack.