Blueberry Poppy Seed Squares, a unique coffee cake in the Eastern European tradition ~ it’s packed with fresh blueberries and crunchy poppy seeds on a buttery shortbread crust. This is one unforgettable snack cake!
This unusual recipe, known as Boruvkový Kolác, or blueberry cake, draws on the baking traditions of Czechoslovakia, Hungary, and Russia. It features a generous layer of crushed poppy seeds mixed with cream spread over a shortbread crust, and topped with cinnamon scented blueberries and a light streusel ~ it’s a good bet you’ve never had anything like it, and it’s wonderful.
I file this recipe under January Baking ~ my favorite kind. January baking is relaxed, and driven only by what I feel like on any given day. I don’t like complicated baking projects, and I’m always on the lookout for new and unusual treats that aren’t too decadent and aren’t difficult to throw together. These bars fit the bill perfectly ~ and the combination of ingredients makes them really special. The purply iridescence of all those poppy seeds just sends me.
There are a few steps to assembling these bars, but nothing you haven’t done a millions times before…except maybe grinding the poppy seeds!
Ground poppy seeds are a common ingredient in Eastern European and Russian desserts, and you can buy them already ground in the form of a paste, if you have access to a specialty market. I ground my own in the dry container of my Vitamix blender in just a few seconds time. You can grind them in a coffee grinder as well. If you can’t grind them, I would use the whole poppy seeds, I don’t think it will make that much difference.
(Note: One of the commenters below suggests using a rolling pin to lightly crush the seeds)
After you lightly pat down a layer of shortbread dough in a 9×13 pan, you top it with a mixture of ground poppy seeds and heavy cream ~ sounds good already, doesn’t it?
Over that, lots of fresh blueberries that have been briefly cooked with some sugar, lemon juice, and cinnamon. It smells wonderful!
The final layer is a simple streusel made with the same shortbread ingredients.
The poppy seeds add a unique savory element to the flavors of these coffee cake squares.
Reader Rave ~
“The pan is in the oven right now. I felt like an artist making this cake, I should have taken a picture.
First the dough end to end, next the poppy seeds, followed by blueberries and ending with the streusel. It was a wonderful experience , that I never felt with other recipes.
Tonight my friends are getting a fantastic treat. Thank you again.” ~Joan
*Recipe lightly adapted from Saveur
Blueberry Poppy Seed Squares
- 2 sticks 1/2 pound or 16 tablespoons unsalted butter at room temperature
- 1/2 cup granulated sugar
- 2 1/2 cups all purpose flour
- 1/2 tsp salt
- 4 tbsp unsalted butter at room temperature
- 1/2 cup all purpose flour
- 1/4 cup granulated sugar
- 1/4 tsp salt
- 3/4 cup granulated sugar
- 2 pints 4 cups fresh blueberries, about 18 ounces
- 2 Tbsp lemon juice
- 2 Tbsp cornstarch
- 1/2 tsp cinnamon
poppy seed layer
- 1 1/2 cups ground poppy seeds grind them in a coffee grinder or high speed blender like Vitamix If you can't grind them, use them whole.
- 1/2 cup heavy cream
- Set the oven to 350F
- Butter and flour a 9x13 pan.
- Cream the butter and sugar together until light and fluffy. Mix in the flour and salt until just combined. Press it into the bottom of your prepared pan. Chill for 20 minutes, then bake for 12 minutes, just until it starts to turn the faintest golden. Set aside to cool.
- Meanwhile put the filling ingredients in a saucepan and bring to a boil, stirring to dissolve the sugar and cornstarch. Turn down the heat and continue to boil for about 15 minutes, or until the blueberries have released their juice and the mixture has thickened a bit. Set aside to cool.
- Use your fingertips to mix the streusel topping together. Break up the butter into small bits to create a nice crumb. Set aside.
- Stir together the poppy seeds and heavy cream. Spread across the bottom of the cooled crust.
- Add the blueberries over the top of the poppy seeds. Top with the streusel.
- Bake for 40 minutes, until it is bubbling and just begging to turn golden brown along the edges. Cool and cut into 16 squares.
Make it your own ~
- You could theoretically leave out the poppy seed layer and just add some to the shortbread dough and streusel for a more subtle poppy seed presence.
- You could use any number of berries in place of the traditional blueberries.
- Frozen berries should work fine.
Don’t forget to pin these Blueberry Poppy Seed Squares!