Signature; traybake
Aleksander pastry, tosca... I do love brownies, as well, and blondies, and... there's so much to choose from!
I think I'd give Brita pie a chance.
Brita pie is a variant of the Brita cake (called Pinocchio cake in Sweden, and The World's Best in Norway. Beloved cake has many names :-D It's surprisingly unutilized in the rest of the world.)
The idea is to bake a golden cake with yolks and top it with meringue made with the whites. It is seriously worth the name "world's best".
4 eggs, separated
200 g / 7 ounces butter
3 dl / 1 1/4 cups sugar, divided
3 dl / 1 1/4 cups flour
1 dl / 7 tbls potato starch
1 tsp baking powder
2 dl / 3/4 cups milk
about 250 grams / 8-9 ounces red currants (or other sour berries, like cranberries)
1 dl flaked almonds
whip the whites to hard peak, with 1 1/2 dl sugar.
Foam softened butter and 1 1/2 dl sugar. Add the egg yolks one at a time. Mix the dry ingredients in a bowl and add to the butter mixture little by little with the milk. Mix thoroughly, but don't overmix.
Spread the batter on oven tray.
Sprinkle the berries on the batter.
Spread the meringue over the berries.
Sprinkle with almond flakes.
Bake in 175°C/350°F oven for about 20 minutes. The cake should be done, the meringue slightly browned and crispy on top.
Decorate with fresh berries, eat with whipped cream.
Technical challenge: tuiles
Showstopper: Biscuit tower
Now, there's a question... krokan, kransekage, or some architectural adventures?
Krokan is practically almond paste that has been softened with egg whites to be spritzable, and then one spritzes curlicues that are then assembled into a tower. Sort of croquembouche.
Kransekage is a classic Danish feast pastry built of different size rings (kranse), so that you get a cone shaped tower. That, too, is almond based dough. (You don't need the discs Glenn had, the Danes use different sized ring shaped pasty cutters.
To me these things are so tightly woven to Scandinavian wedding traditions, that I have difficulties in even seeing them as cookie towers :-D It took Glenn's Helter-Skelter to remind me of that that's exactly what these are. So had I been competing in the actual event, I would not have thought of either, but gone with the architectural thing. Tower of Babel might have been an interesting idea... or Semiramis' hanging gardens. Or Mississauga Absolute Towers. That would have been easy, because it's basically just oval discs stacked on top of each other :-D Or the Uspenski Cathedral...
And there's also like 12 different types of biscuits/cookies/"small cakes" - there's cut cookies, drop cookies, ice box cookies, molded cookies, spritzed cookies, no bake cookies, bar cookies, meringues, twice baked, rolled, wagers, deep fried, waffle cookies... it would be wonderful to make the Uspenski Cathedral with different types of cookies, using the toughest at the bottom, and the most delicate ones as roof and so...