Line bottom of 8 x 8 x 2-inch square pan with aluminum foil; smooth out wrinkles.
In medium-size microwave-safe bowl, heat chocolate in microwave oven at full power for 2 minutes. Whisk until the chocolate is melted and smooth.
Stir cereal and raisins into chocolate until well combined. Spread mixture evenly in foil-lined pan. Refrigerate about 2 hours or until the mixture is firm.
Invert the pan onto work surface; remove pan and peel off aluminum foil. Cut into squares and serve. Squares can be stored in airtight container in the refrigerator. Makes 4-1/2 dozen squares (1-inch).