All in a Portuguese whirl

Today I had one of those ooh aah moments.If there's one single cake that brings back childhood memories, it's this one. Marble cake is a classic childhood cooking memory. There are recipes that are part of the culinary universe as far back as one can remember. One of these is the marble cake, for years it had almost disappeared from my memory, but living in Portugal where this cake is ever popular, not only with children, it all came back to me, and today I finally made my first Bolo mármore, Portuguese chocolate marble cake.As simple as it looks, there´s more to the ins and outs of proper whirling than meets the eye. A marble cake looks slick when you slice into it and reveals the delicate pattern created when the two batters are swirled together.I combed the internet for a recipe that used real cooking chocolate and not cocoa powder and this was a long search, believe me.When I finally found what I was looking for I then had to recast the recipe before I was able to achieve what I was setting out to do.This recipe used rum- ok if I wanted a truly adult cake that would have been fine but remember I was trying to rekindle a childhood memory, and my dear mother would certainly not have plied me with liquor at an early age, let alone the fact she would have been thrifty with her  ingredients in the post ration days of the  fifties. The second element of the recipe I changed was their choice of baking tin. They advocated a tube or Bundt pan.My desired choice was a square cake tin so I could have more geometrically shaped slices when I served it.

Makes one  (20-cm)  square and 8cm deep cake tin, about 24 slices

BASE BATTTER

• 2 2/3 cups all-purpose flour (spoon flour into a dry-measure cup and level off)
• 1 2/3 cups sugar
• 2 teaspoons baking powder
• 1/4 teaspoon salt
• 12 ounces/350 grams (3 sticks) unsalted butter, softened
• 7 large eggs

CHOCOLATE BATTER

• 2 tablespoons dark rum
• 2 tablespoons milk
• 1/2 teaspoon baking soda
• 6 ounces (175 grams) bittersweet (not unsweetened) chocolate, melted and cooled
• 2 cups Base Batter

1 x 20cm square cake tin greased and lined with baking parchment.

Set a rack in the lower third of your oven and heat the oven to 160C/325F.

Combine flour,sugar,baking powder and salt, in the food processor.Pulse quickly to mix.Add the butter and beat on alow speed until you have a smooth heavy paste( 1-2 minutes).

Whisk the eggs together then on medium speed introduce them gradually into the flour and butter mix, beat for 1 minute,scraping  down the beater bowl in between each introduction of the egg mixture.When all the egg mixture has been added beat for a further 2 minutes.Remove the bowl and set aside.

Combine the milk and baking soda in a medium mixing bowl.Whisk well to dissolve the soda. Scrape in the chocolate and whisk well. Add 2 cups of the base batter to the chocolate mixture and whisk again to combine. Scrape half the remaining base batter into the prepared tin and smooth the surface.Cover with the chocolate batter making another layer as even as possible.Top with the remaining base batter and smooth the top.Using a wide bladed table knife or metal spatula draw the blade through the batter to the bottom of the pan and up and out of the side of the pan closest to you, repeating the motion every inch or so around the pan, making a spiral in the batter, almost as though you were folding egg whites into it. Stop when you get back to the point where you started. Don't bother to smooth the top of the batter—it might disturb the marbling.

Bake the cake until  it is well risen and firm, and a toothpick or a small thin knife or skewer emerges dry, about 1- 11/2 hours.Cool the cake in the pan on a rack until completely cooled then invert it and carefully peel the baking parchment away.Place a square plate over the cake and invert it back onto the plate.Now is your oooh aah moment.