Beat butter at medium speed with an electric mixer until creamy; gradually add sugar and 1/2 cup brown sugar, beating well. Add egg substitute, beating well.
Combine flour, 1 teaspoon cinnamon, and next 3 ingredients; add to butter mixture alternately with buttermilk, beginning and ending with flour mixture. Mix well after each addition. Spoon half of batter into a greased and floured 13- x 9-inch pan.
Combine remaining 1/2 cup brown sugar, remaining 1/2 teaspoon cinnamon, nutmeg, and walnuts; sprinkle half of mixture over batter, and top with cranberries. Top with remaining batter, and sprinkle with remaining brown sugar mixture.
Bake at 350° for 35 minutes or until a wooden pick inserted in center comes out clean. Cut into squares, and serve coffee cake warm.