Happy St. Patrick’s Day!

I know . . . I’m slow . . . but you can still make these today.

What’s better than a chewy, gooey brownie topped with swirls of Marshmallow or Fudge frosting?

Not much.

This brownie is my favorite, it’s the Katharine Hepburn brownie.

I simply made homemade Marshmallow frosting for the top.

I’ve had a few emails regarding making the Marshmallow frosting, and so I thought I’d do a fast tutorial. This is not to be mistaken with the Homemade Marshmallows post.  This recipe is frosting, and it’s really yummy!

I started by making some SQUARE brownies . . . in these fabulous square pans.

As long as you grease the squares with cooking spray . . . They come out like very easily.

See .

I doubled the recipe below, and was able to make about 20 squares.

The ones on the left have big chunks of Walnuts . . . the right . . . plain Jane.

Let them cook on parchment paper, while you make the Marshmallow.

Use a Your Kitchen Aid is you have one or a heavy hand mixer.

You will need egg whites at room temp . . . Karo Syrup, Sugar, salt and Vanilla

I also am using a bit of green gel paste and a few sprinkles.

You will also need a pastry bag and the tips you would like to use.

Turn the speed on high and start by whisking your egg whites . . . just until they are good and frothy.

like this . . .

Leaving your speed on med. high . . . slowly, slowly add your sugar.

Beat it until it is thick, glossy and firm.

You can make peaks at this point . . . but they aren’t STIFF.

Now very, very, very slowly add the Karo Syrup.

I kept my speed at about 8.  (medium high)

Once you have all the Light Karo Syrup incorporated, stop the mixer for a second.

You need to scrape down the sides of the bowl.

Now go ahead and turn the mixer on Full Blast.

Once you have stiff, stiff, stiff peaks . . . Add the vanilla, and mix again.

It should look like this!

I wanted to have different colors of swirls when I piped it on the brownie.

So . . . I divided the Marshmallow in half.

Half white  and added Green gel paste to the other half.

Mix it until it’s well blended in your stand Mixer again.

Now I have a pretty green color for St. Patrick’s Day!

Get your Pastry bag ready with the tip you want to use.

I used a Closed Star Tip:  2D

Try to lay one side of the pastry bag with white Marshmallow and one side green.

It doesn’t have to be perfect . . . This stuff is sticky!

Twist the top of the bag tightly until the Marshmallow starts to come out of the tip.

Pipe from the outer edges to the center . . . trying to keep the square shape.

Use a few sprinkles on top before the Marshmallow Frosting sets up.

You can do a lot . . . or a little for Husband’s like mine!

See the pretty green & white swirls.

These will also be fun for Easter in bright colors, like Orange, Purple & Pink.

So easy and So Delicious.

Luck of the Irish to you!




  • Beat together:
  •  2 egg whites and 1/4 tsp. salt  until very very Frothy.
  • Slowly add:
  • 1/4 cup white sugar and Beat until very smooth thick and glossy.
  • Slowly add:
  • 3/4 Cup light Karo Syrup and Beat until stiff Peaks form.
  • Gently:
  • Fold in 1 tsp. Pure Vanilla
  • Frost 8×13″ cake or pipe on 12 to 15 cupcakes
  • Don’t cover cake tightly.






If you want a dense chewy brownie, this is the recipe for you.  They are delicious!


  • 1/2 cup (1 stick) butter
  • 2 oz. unsweetened chocolate, chopped  (I only added 1 ounce of unsweetened chocolate)
  • 1 cup sugar
  • 2 large eggs, slightly beaten
  • 1 tsp. pure vanilla extract
  • 1/4 cup all purpose flour  ( I added 1/2 cup of flour)
  • 1/4 tsp. salt
  • 1 cup walnuts, chopped


1.  Position a rack in the middle of the oven.  Preheat the oven to 325 degrees.  Butter and flour and 8″ square baking pan or line your pan with parchment paper for easier cutting after baking.

2.  Melt butter and chocolate in a heatproof bowl set over a saucepan of about 1 1/2″ of nearly simmering water, whisking until smooth.  Or melt in a microwave – watching closely.

3.  Remove the bowl from the heat, sugar, eggs and vanilla, whisk until well blended.  Whisk in the flour and salt just until well blended.  Stir in the walnuts.  Transfer the batter to the prepared floured pan.

4.  Bake for 35 to 40 minutes, or until a wooden pick inserted in the center comes out sticky, with just a few crumbs clinging to it, but is not wet.  Do Not Overbake. The edges start to pull away from the sides of the pan as well.  Don’t over bake!

5.  Optional:  Add mini marshmallows to the top of the brownies, and put back into the oven……just until they begin to melt slightly.  Don’t brown.

6.  Let Cool for 5 to 10 minutes, and spread or drizzle fudge frosting over the top.  I put my brownies in the fridge to cool for about 20 – 30 minutes before cutting them.




Fudge frosting that delicious, creamy and smooth.  It’s hard to resist eating this with a spoon!


  • *This recipe makes enough frosting for a double batch of brownies in a 9×13 ” pan. It’s also more like a glaze – if you want it thicker, simply add more powdered sugar.
  • 1 3/4 sticks butter
  • 4 Tablespoons cocoa powder (I only used 3)
  • 6 Tablespoons milk
  • 1 tsp. vanilla extract
  • 1 pound powdered sugar
  • 1/2 cup finely chopped pecans or walnuts (opt)




1.  Melt the butter in a medium sized saucepan over medium-low heat.

2.  Add the cocoa powder and stir until smooth.

3.  Add the milk, vanilla and powdered sugar.  Whisk until very smooth.

4.  optional:  Add the chopped nuts and stir until well combined.



This frosting is quite thin . . . if you want it a bit thicker simply add more powdered sugar.  It’s yummy!  I just drizzle the fudge frosting over the top of the Marshmallows.  Put the remaining frosting in a container, and store in the fridge for later use.











  • Brandi - 03/17/2011 - 4:23 pm

    Those look simply delicious! Your mashmallow frosting looks a lot better then mine did that humid day I tried it! I think the chewy brownie with the marshmallow frosting is the perfect combination!ReplyCancel

  • Blog is the New Black - 03/17/2011 - 4:59 pm


  • Steph - 03/18/2011 - 8:26 am

    I love marshmallow frosting! If you worry about the raw eggs (like I do) you can wish egg whites and sugar in a double boiler until it reaches about 160 degrees before whipping. Delicious!ReplyCancel

  • merium - 03/18/2011 - 9:55 am

    I love Katherine Hepburn’s Brownies! Must make this marshmallow frosting soon! Where did you find the square pans? I’ve been looking, but haven’t come across them yet.ReplyCancel

    • Jonna - 03/18/2011 - 10:06 am

      Hi Merium,
      I found the square pans at Kohls and Target.
      Hope you can find them in your area . . . They are a lot of fun!

  • Shannon Carter - 03/18/2011 - 7:11 pm

    Mom…THANKS for the brownies! They were so good! They were gone the same day. That’s how good they were. Thanks for all the treats. Luv You!ReplyCancel

  • Diana B - 03/19/2011 - 12:16 pm

    Wow, those brownies are to DIE for, I’ve made them many times…but with that marshmallow frosting..I can’t WAIT!!! Someone mentioned the raw egg whites in the comments…does anyone know if you still have to worry about just the egg whites if you’re pregnant?? I want to try that mallow frosting so badly!!!ReplyCancel