Equal rhubarb cake

I've got a new favourite to-go rhubarb cake recipe. Just because it's one that can be memorized in seconds. Actually you just need kitchen scales and the list of ingredients. No amounts, imagine :)

Here's how it works. I call it equal rhubarb cake, because you need equal weighed amounts of all the main ingredients. I usually take four eggs, chicken or duck, to make this cake. 

Rhubarb sheet cake

(Võrdne kook rabarbriga)

eggs

butter, at room temperature*

caster sugar 

all-purpose flour

rhubarb, thinly sliced 

Topping:

demerara sugar and cardamom

Line a baking sheet with a parchment paper/baking paper (if the eggs are large, you can use a large baking sheet, say 35x40 cm, if the eggs are smaller, I tend to use 25x35 cm).  Put aside. 

Put a bowl onto your kitchen scales, switch the scales on and break eggs into the bowl. Weigh the eggs - and remember the number. Put the eggs aside, take another bowl. 

Now, remember the weight of eggs? Add the same amount of butter into the mixing bowl, then the same amount of sugar. Mix the butter and sugar until pale and creamy.

Now add the eggs, one at a time, and mixing thoroughly after each egg. Fold in the same amount of flour. 

(So if your eggs weighted, say, 250 grams, you'll also need 250 g butter, 250 g sugar, 250 g flour and about 250 g rhubarb). 

Now spread the dough mixture onto the baking sheet. Spread the rhubarb evenly across the cake, then sprinkle with demerara sugar and ground cardamom. 

Now bake at 200 C/400 F for about 20 minutes, until cooked and nicely golden. Let cool a little, then cut into squares, dust with icing sugar and serve. 

Keeps well for a day or two, covered.