Dreamsicle Fudge

My mom made these for Christmas a few years ago. I kind of feel like the recipe needs a few tweaks. It's not very fudge-like and everyone I know who has made it has the same struggles I had (it's kind of dry and crumbly). This time that I made it it was kind of grainy even though I cooked it long enough (wondering if it was because I was making a double batch that I should have cooked it just a bit longer). I'm not a wonderkin when it comes to this stuff, so I probably won't mess with it.

2-3 tsp. orange flavoring
9 drops red food coloring
12 drops yellow food coloring [on that note, I used a few drops of orange AmeriColor gel paste]
1 1/2 sticks (3/4 cup) butter
2/3 cup evaporated milk
3 cups sugar
1 (12 oz.) pkg. white chocolate chips
7 oz. marshmallow cream

Mix orange flavoring, red food coloring and yellow food coloring and set aside.
 
Boil butter, evaporated milk and sugar for 5 minutes. Add white chocolate chips and marshmallow cream. Mix well.
Reserve 1 cup white mixture.

Add orange flavoring to remaining mixture. Pour into a 13x9 buttered glass dish.

Swirl the cup of white into mixture. Allow to cool completely before cutting into 1" squares.