Line an 8-inch square baking dish with parchment paper. Set aside.
Prepare your mixing bowl by adding the marshmallow cream and white chocolate chips. Set aside.
In a large saucepan over medium high heat, combine sugar, cream, butter and salt. Bring to a boil. Stirring constantly, boil for a full 4 minutes (ROLLING BOIL). Remove from heat.
Immediately pour hot mixture over marshmallow and white chocolate chips in mixing bowl. Using your electric mixer, blend until smooth (and white chocolate morsels are melted, about 1 minute).
While blending, crumble half of the frozen cookie dough (in small 1/2-inch chunks) into the bottom of your baking dish. Pour hot mixture over frozen cookie dough. Immediately press the remaining frozen cookie dough into the top of the fudge, in small 1/2-inch chunks.
Refrigerate for 3-4 hours until firm. Cut into small pieces and enjoy.
Notes
Bring to a rolling boil. The heavy cream mixture needs to cook at a full boil for 4 minutes to achieve the right consistency. Stir it constantly while it cooks.
Mixing in cookie dough: Crumble half of your frozen cookie dough over the bottom of the baking sheet first. Then pour the fudge mixture on top and press the remaining chunks of dough on top.
Use frozen cookie dough. The fudge mixture will be warm when you pour it over the dough. If the dough isn’t frozen, the cookie dough will spread and get gooey. Frozen dough will thaw to a soft and edible texture.