Key Lime Pie Fudge

Ingredients

• Graham Cracker Crust
• 4 tablespoons margarine or 4 tablespoons butter, melted
• 2 tablespoons sugar
• 3/4 cup graham cracker crumbs
• Fudge
• 2 cups white chocolate candy melts
• 300 ml sweetened condensed milk (one small can, a little over a cup)
• 3 tablespoons lime zest (about 3 limes worth or 6-8 key limes)
• 3 tablespoons lime juice (freshly squeezed is better)
• 1/2 teaspoon citric acid (you can find it in health food stores)
• 3 -5 drops food coloring (optional, i used 3 drops of green and 2 of yellow)
• 1/2 teaspoon vanilla extract