Combine water and margarine in a medium saucepan; bring to a boil. Reduce heat; add flour and garlic salt, stirring vigorously over low heat until mixture leaves sides of pan and forms a smooth ball, about 1 minute. Remove from heat.
Add egg substitute to flour mixture, beating with a wooden spoon until smooth. Stir in zucchini and cheese.
Drop by heaping tablespoonfuls onto a baking sheet coated with cooking spray. Bake at 400° for 22 to 24 minutes or until puffed and golden.