Polish Sand Cake (Biszkopt Piaskowy)

If you grew up in a Polish household, there’s a good chance you’ve had Biszkopt Piaskowy, also known as Polish Sand Cake. This nostalgic dessert is known for its light, airy texture and signature “sandy” crumb thanks to the addition of potato starch. Unlike a rich butter cake, this traditional sponge is intentionally delicate and slightly dry—which is exactly what makes it perfect for soaking up juicy strawberries and fresh whipped cream.

One thing to know before baking: this cake is not your typical moist sponge cake. Its crumbly texture is what gives it the name Sand Cake. Once topped with homemade whipped cream and sweet macerated strawberries, the cake softens beautifully. In fact, I think it tastes even better the next day after the strawberry juices have had time to soak into every bite.

Why You’ll Love This Recipe

• A traditional Polish dessert that’s been loved for generations.
• Light, airy, and perfectly delicate.
• Made with simple pantry staples.
• The perfect way to showcase fresh summer strawberries.
• Even better the next day.
• Beautiful enough for holidays, birthdays, and family gatherings.

Ingredients You’ll Need

For the Cake

• Eggs – The foundation of this sponge cake. Separating the yolks and whites creates an incredibly light texture.
• Granulated sugar – Sweetens the cake while helping create a fluffy batter.
• Vanilla sugar – A staple in many Polish desserts that adds delicate vanilla flavor. I use one 9 g packet.
• All-purpose flour – Gives the cake structure.
• Potato starch (potato flour) – The secret ingredient that creates the signature sandy texture this cake is known for.
• Baking powder – Gives the sponge a little extra lift.

For the Whipped Cream

• Heavy whipping cream – Whips into a light, fluffy topping.
• Powdered sugar – Lightly sweetens the whipped cream.
• Pinch of salt – Balances the sweetness and enhances the flavor.

For the Strawberries

• Fresh strawberries – Sweet, juicy, and perfect during strawberry season.
• Granulated sugar – Draws out the strawberry juices to create a delicious syrup that soaks into the cake.

Tips for Success

• Separate your eggs carefully. Even a small amount of egg yolk can prevent the whites from whipping properly.
• Beat the egg yolks until pale and fluffy. This step incorporates air into the batter and creates a lighter sponge.
• Whip the egg whites to stiff peaks. When you lift the beaters, the peaks should stand straight up without folding over.
• Fold the egg whites in gently. Use a rubber spatula and fold just until combined to keep as much air in the batter as possible.
• Line your cake pan with parchment paper. This helps the delicate sponge release easily after baking.
• Don’t expect a moist cake. Biszkopt Piaskowy is traditionally known for its slightly dry, crumbly texture—that’s exactly how it’s supposed to be!
• Don’t skip macerating the strawberries. Their natural juices create a syrup that soaks into the cake and transforms its texture.
• Make it a day ahead. This cake is even better after sitting overnight in the refrigerator, allowing the whipped cream and strawberry juices to soften the sponge.

Frequently Asked Questions

Why is it called Sand Cake?

The addition of potato starch gives the cake its delicate, sandy crumb, which is where the name “Sand Cake” comes from.

Is the cake supposed to be dry?

Yes! Unlike a traditional butter cake, Biszkopt Piaskowy is intentionally light and slightly crumbly. Once topped with whipped cream and juicy strawberries, it softens beautifully.

Can I make it ahead of time?

Absolutely! I actually recommend making it a day in advance so the strawberry juices have time to soak into the cake.

Can I freeze it?

Yes! Freeze the plain cake layer before adding the toppings. Once thawed, decorate with fresh whipped cream and strawberries.

Storage

Store the assembled cake covered in the refrigerator for up to 3 days.

Freezing

Freeze the plain cake layer (without whipped cream or strawberries) for up to 2 months. Wrap tightly in plastic wrap and foil before freezing.

Shop My Baking Essentials

These are a few of my favorite baking tools that make this Polish Sand Cake Puszysta Babka Piaskowa easy to prepare and beautifully finish with homemade whipped cream and fresh strawberries.

As an Amazon Associate, I earn from qualifying purchases. I may earn a small commission when you shop through my links, at no additional cost to you. Thank you so much for supporting Bonia Bakery! 

9-Inch Round Cake Pan — Perfect for baking the sand cake evenly while giving it that classic round shape.

Parchment Paper — Makes lining the bottom of the cake pan easy and helps the cake release cleanly.

Silicone Spatulas — Great for gently folding the whipped egg whites into the batter without knocking out too much air.

Stand Mixer — Makes quick work of whipping the egg whites and preparing the fluffy homemade whipped cream.

Digital Kitchen Scale — My go-to for accurately measuring ingredients, especially for Polish and European-style baking.

Ingredients

Polish Sand Cake

• 4 large eggs, separated
• 1 cup (200 g) granulated sugar
• 1 packet (9 g) vanilla sugar
• ½ cup (60 g) all-purpose flour
• ½ cup (80 g) potato starch (potato flour)
• 1 teaspoon baking powder

Whipped Cream

• 1 cup (240 g) cold heavy whipping cream
• 1 tablespoon powdered sugar
• Pinch of salt

Macerated Strawberries

• 2 cups fresh strawberries, hulled and sliced
• 2 tablespoons granulated sugar

Instructions

Make the Cake

1. Preheat the oven to 350°F (175°C). Grease a 9-inch round cake pan and line the bottom with parchment paper.
2. Separate the egg yolks and egg whites into two large mixing bowls.
3. Beat the egg yolks with the granulated sugar and vanilla sugar until the mixture becomes pale, thick, and fluffy.
4. Add the all-purpose flour, potato starch, and baking powder. Mix until fully combined.
5. In a separate clean bowl, beat the egg whites until stiff peaks form.
6. Gently fold the whipped egg whites into the batter in three additions using a rubber spatula. Fold only until no white streaks remain.
7. Pour the batter into the prepared cake pan and smooth the top.
8. Bake for 35–40 minutes, or until a toothpick inserted into the center comes out clean.
9. Allow the cake to cool completely before decorating.

Make the Strawberries

10. While the cake cools, combine the sliced strawberries and granulated sugar in a bowl. Stir well and let them sit for 20–30 minutes until juicy.

Make the Whipped Cream

11. In a chilled mixing bowl, beat together the heavy whipping cream, powdered sugar, and a pinch of salt until medium-stiff peaks form.

Assemble

12. Spread the whipped cream evenly over the cooled cake.
13. Spoon the macerated strawberries and all of their juices over the whipped cream.
14. Slice and serve immediately, or refrigerate overnight for the best flavor. As the cake rests, it absorbs the strawberry juices and becomes even more delicious the next day.