Marian's Sour cream poppy seed muffins

2 c. Flour 1/4 c. Poppy seeds 1/2 tsp salt 1/4 tsp baking soda 1/2c butter 3/4 c sugar 2 eggs 3/4 c sour cream 1 1/2 tsp vanilla Mix dry ingredients together and set aside. Beat butter and sugar until fluffy. Add eggs and beat. Add sour cream and vanilla, mix. Combine w flour mixture until smooth. Bake 20 min at 375