In a medium sized bowl, sift together the flour, salt, baking powder, and baking soda. Gradually add dry ingredients to the wet ingredients beating over low speed.
Pour half of the batter into prepared pan. Sprinkle with half of the streusel mixture then top with remaining batter. Sprinkle the rest of the streusel mixture over the top.
Bake in preheated oven for 50-60 minutes until cake is cooked through and a toothpick inserted near the center comes out clean. Cool completely on a wire rack.