Preheat oven to 350 degrees. For batter, cream margarine and sugar. Add eggs and beat well. Add dry ingredients. Stir to combine. Spread 2/3 of batter into flat bottom of springform pan. Blend cheese filling ingredients. Spread evenly over batter. Spread remaining batter on top. Mix the streusel topping to a coarse crumb texture. Sprinkle the streusel on top. Bake for 45 minutes.