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 is known as Boruvkový Kolác, or blueberry cake
It 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 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.
poppy seeds add a unique savory element to the flavors of these coffee cake squares.
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.
You will need more than a small jar of poppy seeds for this recipe, and you can always find them in bulk, online, HERE. To store extra poppy seeds, put them in an airtight container in the refrigerator (6 mos) or freeze them, (1 year).
what you’ll need
- poppy seeds
- lemon juice
how to assemble blueberry poppy seed bars
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!
- Lightly pat down a layer of shortbread dough in a 9×13 pan
- 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.
Blueberry Poppy Seed Squares
- 1 cup 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 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, see notes below
- 1/2 cup heavy cream
- Set the oven to 350F
- Butter and flour a 9×13 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.
- Grind poppy seeds in a coffee grinder or high speed blender like Vitamix. If you can’t grind them, use them whole.
- One of the commenters below suggests using a rolling pin to lightly crush the seeds.
- 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