Cream together butter, 2 cups of sugar, and eggs. Add milk, flour, and baking soda.
Put half of the batter into two greased loaf pans (1/4 in each pan).
Mix in separate bowl the cinnamon sugar mix. Sprinkle 3/4 of cinnamon mixture on top of the batter in each pan.
Add remaining batter to pans; sprinkle with last of cinnamon topping. Swirl with a knife.
Bake at 180 degrees for 40-45 min. or until toothpick tester comes out clean.
Cool in pan for 20 minutes before removing from pan.