Preheat oven to 350°.
Lightly spoon flour into dry measuring cups; level with a knife. Combine flour, soda, and salt in a bowl. Place banana and next 3 ingredients in a bowl; beat with a mixer at medium speed until blended. Add flour mixture; stir just until moist. Stir in dates. Pour batter into an 8 x 4-inch loaf pan coated with cooking spray.
Combine brown sugar, 2 tablespoons flour, and cinnamon in a small bowl. Cut in butter with a pastry blender until mixture resembles coarse meal. Sprinkle evenly over batter.
Bake at 350° for 50 to 55 minutes or until a wooden pick inserted in center comes out clean. Cool in pan on a wire rack 10 minutes; remove from pan, and cool completely.