Combine the brown sugar, butter, honey, and egg whites in a large bowl; beat with an electric mixer at medium speed until well blended. Beat in the flour, cinnamon, and baking powder. Stir in the cereal, raisins, and sunflower seeds.
Press the mixture firmly into a greased 13 x 9 x 2-inch baking pan; bake for 20 minutes, or until the edges are lightly browned and the center appears set. Let cool completely in the pan on a wire rack. Cut into bars.