Preheat oven to 350ºF.
In a large mixing bowl, beat 1 cup sugar and 8 oz butter until creamy.
Add eggs, baking soda, salt, milk, and vanilla. Beat again.
Add 2 cups flour and beat until batter is smooth.
Stir in rhubarb and pecans.
Transfer batter to a greased bread pan.
In a small bowl, mix melted butter, sugar, flour, and cinnamon. The consistency will be a paste like crumble.
Sprinkle crumble evenly over batter.
Bake for 60 minutes or until a toothpick comes out clean.