Ingredients:
4 oz chocolate chips
1 1/2 sticks (3/4 cup) unsalted butter
1 cup sugar
3 eggs
1 tsp vanilla
1/4 tsp salt
1 cup flour
1/2 cup white chocolate chips
1 cup marshmallow creme

Directions:
Heat oven to 350F

Grease a 8″X8″ pan and set aside

In a large pot over medium heat, combine chocolate and butter and melt to combine, whisking frequently to ensure chocolate does not burn or separate from butter (alternatively, you can use a double boiler).

Once the chocolate is completely melted, remove from heat and stir in sugar. Add eggs one at a time, whisking to blend after each addition. Add vanilla, flour and salt. Stir until just combined.

Stirwhite chocolate chips. Pour batter into prepared pan. Swirl in the marshmallow creme, make a figure 8 pattern to swirl the creme into the batter.

Bake for 30-35 minutes, or until a knife inserted in the center comes out with a few crumbs.

Let cool before eating.

Source: grandmotherskitchen.org