Preheat oven to 350°.
To prepare cake, coat a 9-inch square baking pan with cooking spray; set aside.
Lightly spoon 2 cups flour into dry measuring cups; level with a knife. Combine 2 cups flour and next 5 ingredients (through cinnamon) in a large bowl; make a well in center of mixture. Combine 5 tablespoons butter and the next 4 ingredients (through eggs) in a medium bowl; beat with a mixer at medium speed until blended. Add to flour mixture; stir just until moist. Stir in dates. Spoon batter into prepared pan.
To prepare topping, combine sliced almonds and remaining ingredients, stirring with a fork until blended. Sprinkle evenly over batter. Bake at 350° for 35 minutes or until a wooden pick inserted in center comes out clean. Cool completely in pan.