Švestkový Koláč (Plum Cake)

For those of you who are already familiar with my grandmother's cooking, you've been waiting for this recipe!  My grandmother's Plum Cake is legendary.  The key is an electric mixer (handheld is fine but KitchenAids are pretty great!) and an electric scale.

For the streusel topping, you will need:
150g flour (preferably Wondra brand, but all-purpose is fine)
100g sugar
100g margarine
Rind of half a lemon

For the dough, you will need:
250g sugar
250g margarine
1 tsp vanilla extract
5 eggs, separated
Pinch of salt
250g all-purpose flour
1/2 tsp baking powder
Rind of the other half of your lemon
And finally, nice italian plums. But you can also use cherries or blueberries.

First combine your streusel topping with your hands until it becomes a neat crumble.  Then set it aside.

Next, start the dough.  Begin to whip together your sugar, margarine, and vanilla extract with an electric mixer.

Beat it until it is creamy and fluffy, almost like lemon frosting.  Separate your egg whites from your yolks, dropping only the yolks into the mixer one by one, waiting at least a moment or two between each one. Let it keep beating until it's almost as thick as mousse.

This is a great time to preheat your oven to 350 degrees and grease and also flour your baking sheet.

Separately, mix your dry ingredients (flour, baking powder, and lemon rind).  Sorry I didn't take a picture of that.

Also separately, sprinkle a pinch of salt and beat your five egg whites into thick peaks, just past soft peaks.

Put your dough bowl in front of you and toss in 3-4 heaping tablespoons of your dry ingredients and a massive spoonful of beaten egg whites.

Fold into your dough until completely combined. Repeat until you run out of dry ingredients and eggs (preferably at the same time).

Spoon your dough onto your greased and floured baking sheet and smooth it out with a spatula.

Split the plums (blueberries and cherries, if you're using those instead, can remain whole) and gently press them into the dough.

Tip: My grandmother tears her plums in half, but I prefer to slice the around their groove and then twist them apart.

Sprinkle your streusel lightly on top.

Then bake for about 40 minutes.  The dough should be golden bordering on brown at the edges (not the pale gold of a normal cake).

Let it cool overnight and cut it the next day.  Keep it covered with a few sheets of paper towels but otherwise you can keep it on your countertop for a few days.