Mix cereal with half cup sugar, the instant coffee and cinnamon; set aside. Mix flour with 1 cup sugar, the baking soda, baking powder and salt in large mixer bowl. Add sour cream, butter, eggs and vanilla. Blend at low speed with electric mixer, then beat for 1 minute at medium speed. Spread one third of the batter in a greased 20 cm square pan; sprinkle with half of the cereal mixture. Repeat layers and top with remaining batter. Bake at 180ºC or 45 to 50 minutes, or until tooth pick inserted into the center comes out clean. Cool in pan; spread with coffee glaze. Coffee glaze: Gradually blend 2 tb cooled brewed Maxwell House coffee into 1.5 cups sifted confectioners sugar. Makes enough to glaze the top of an 8 or 23 cm square cake or 25 cm tube cake.