Marshmallow Ripple Brownies

Though I have had brownies like this before, I have never tried to make them.  But I wanted something with marshmallows and chocolate.  These fit the bill pretty perfectly.

Makes 24 bars

3/4 cup butter
4 oz unsweetened chocolate
1 1/2 cup sugar
3 eggs
1 teaspoon vanilla
1 1/4 cup flour
2 cups miniature marshmallows

1/2 cup brown sugar
1/4 cup water
1 oz unsweetened chocolate
1 tablespoon butter
1 teaspoon vanilla
1 1/2 cup powdered sugar

1. Grease a 9x13 inch pan and set aside.
2. In heatproof bowl, microwave butter and 4 oz unsweetened chocolate for one minute.  Stir well.  If chocolate is not fully melted, heat for another 30 seconds and stir until melted.  Let cool 5 minutes.
3. Stir sugar into butter-chocolate mixture.  Add eggs, one at a time, until batter is smooth.  Add vanilla and stir well.  Beat in flour just until combined. Pour batter into prepared pan and smooth until even.
4. Bake brownies for 30 minutes or until a toothpick inserted in the center comes out clean.  Top brownies with marshmallows immediately and return to oven for 3 minutes more.  Remove to a cooling rack until brownies are cool.
5. Bring brown sugar, water, and 1 oz unsweetened chocolate to a boil in a small saucepan.  Stir mixture occasionally while it is coming to a boil.  Stirring constantly, boil mixture for 3 minutes.  Remove saucepan from heat and add tablespoon butter and vanilla to mixture.  Stir until butter is melted, then add powdered sugar.  Beat until smooth and drizzle over marshmallows on brownies.  Smooth slightly on brownies and allow to cool.  Frosting should harden before cutting brownies into bars.