Raspberry Coffee Fudge

1/4 pound butter
1 (12 ounce) can evaporated milk
3 1/2 cups granulated sugar
1 heaping tablespoon instant coffee granules
1 (10 ounce) package Hershey's Raspberry chocolate chips
2 ounces bittersweet chocolate
1 (7 ounce) jar Marshmallow Cr