Poppy-seed Cake

INGREDIENTS

Ingredients for the dough:
1/3 cup (50 grams) dry poppy seeds
¾ cup (180 ml) milk
¾ cup (175 grams) butter, at room temperature
1½ cups (300 grams) crystal sugar
2 cups (300 grams) all-purpose flour (D: type 550; F: type 55)
1½ teaspoons (real) vanilla extract
2½ teaspoons baking powder
¼ teaspoon salt
4 eggs whites (keep the yolks for the filling!) - if you are using small eggs: use 5 eggs!

EQUIPMENT & SUPPLIES

Hand-mixer
Small bowl
Large bowl
Wire whisk (for loosening the flour and removing clumps - if any; this is a lot quicker and easier (incl. cleaning) than using a sifter!)
Medium size sauce pan
Round cake pan (8 inch / 20 cm diameter)
Cake cooling rack
Sharp bread knife or long, thin filleting knife

PREPARATION / DIRECTIONS

Instructions for the cake
Soak the poppy seeds in the milk for 1 hour
Pre-heat the oven to 190 °C (375 °F)
In a large bowl, cream the butter with the hand-mixer
Gradually add the sugar gradually, and continue creaming until fluffy
Blend in the milk & poppy seed mixture, and the vanilla
Mix in the dry ingredients (flour, sugar, baking powder)
Stir until a creamy mixture is obtained
In a separate bowl, beat the egg whites until quite stiff
Adding ¼-½ teaspoon Cream of Tartar powder ( = potassium bi-tartrate, also potassium hydrogen tartrate; it is one of the two ingredients of a component of baking powder, the other one being baking soda) to the unbeaten egg whites will help stiffen & stabilize them
Fold in the egg whites
Pour the dough/batter into the greased & floured cake pan
Bake for 20-25 minutes - while baking, make the filling!
Let cool for 10 minutes
Remove the cake from the pan and cool on rack
Slice the cake horizontally into 4 equal-thickness layers (i.e., cut 3 times - see photo below!)
Spread the cream filling between the layers, and re-assemble the cake
Chill for 2-3 hours
Just before serving, dust with powdered sugar

Instructions for the filling
In a saucepan, combine the sugar and cornstarch
In a bowl, mix the milk with the egg yolks, and gradually add the milk mixture to the sugar mixture, stirring well
Cook over medium heat until the mixture thickens and bubbles - stir regularly!
Cook for 1 more minute - stir regularly!
Stir in the vanilla
Allow to cool before filling the cake layers

NOTES

The a mount of sugar that this US recipe calls for, may be (way) too much for European taste - reduce by 25% if you are so inclined.