1 c. milk
1 tbsp. vinegar
1 1/2 c. brown sugar
1/2 c. butter
1 egg
1 tsp. vanilla
2 c. flour
1 tsp. soda
1 1/2 to 2 c. finely cut rhubarb

Add vinegar to milk and set aside. Cream butter and sugar until blended. Add egg and vanilla and mix. Sift together flour and soda; add to batter alternately with milk, blending well after each addition. Stir in rhubarb. Pour into greased and floured 8x12 inch pan. Sprinkle top of batter generously with sugar and cinnamon before baking. Bake at 350 degrees for 35-40 minutes until cake tests done with toothpick.