Brush six one cup prep bowls with melted butter and sprinkle evenly with sugar. Thinly cut 6 slices of lemon and place on into bottom of each bowl.
Zest the other lemon. Save 1 tablespoon of zest for the glaze and add all of the remaining zest into the cake mix. To the mix, add 1 tablespoon melted butter, egg and sour cream. Mix until smooth. Scoop batter evenly into prepared bowls. Place bowls in a circle on the microwave turntable. Microwave on high for 5 minutes. Carefully remove cakes from microwave using hot pads or dish cloths.
For glaze, juice the lemon used for zesting and add to 2 tablespoons melted butter and 1/4 cup sugar. Stir well.
To serve, gently tap tops of bowls (I like to do it to a tune) to release each cake onto a dessert plate. Drizzle glaze over cakes and serve warm. Yum.