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There’s something about speculoos spice that smells like a Christmas market, even in July.
These bars started as a way to use up an open packet of Lotus Biscoff biscuits sitting on my counter. One test bake later and I was hooked. The base is buttery and crisp, the middle soft and warmly spiced, and the top gets a faint crunch from a brown sugar sprinkle.
Speculoos biscuits are a Belgian staple, traditionally baked around St. Nicholas Day in early December. The spice blend, heavy on cinnamon and clove, is what makes them unmistakable. When you grind them into a crust and fold the same spice into a sponge batter, the whole bar tastes like one coherent thing.
You need one bowl, one pan, and about 40 minutes, much like these chewy salty-sweet rice bars that come together just as quickly.
Why You’ll Love This Recipe
- Ready in 40 minutes with minimal washing up
- Warm speculoos spice in every layer, crust to top
- Holds its shape cleanly, great for gifting or sharing
- Make-ahead friendly, bars keep well for four days
Ingredient Notes
- Speculoos biscuits (Lotus Biscoff): Lotus Biscoff is the easiest to find brand. Any crisp speculoos-style biscuit works. Avoid soft cookie butter spread for the crust as it won’t firm up properly.
- Speculoos spice blend: A mix of cinnamon, clove, cardamom, nutmeg, and white pepper. If you can’t find a pre-made blend, use 1 tsp cinnamon, 1/4 tsp ground cloves, 1/4 tsp cardamom, and a pinch of nutmeg.
- Light brown sugar: Brown sugar adds moisture and a mild caramel note that pairs well with the spice. Dark brown sugar works and gives a deeper, more molasses-forward flavor.
- Unsalted butter: Melted butter goes into both the crust and the batter. Salted butter is fine, just skip the added salt in the recipe.
- All-purpose flour: Plain flour gives a soft, dense crumb that holds together when cut. Cake flour makes the bars slightly more delicate but still sliceable.
- Eggs: Two large eggs at room temperature. Cold eggs can make the batter look split, though it bakes out fine.
Belgian Speculoos Cake Bars
Ingredients
Method
- Heat the oven to 175 C / 350 F. Line an 8x8 inch baking pan with parchment paper, leaving an overhang on two sides.
- Crush the speculoos biscuits in a food processor until fine crumbs form, or seal them in a zip-lock bag and crush with a rolling pin.
- Mix the crushed biscuits with 80 g melted butter and 1 tbsp brown sugar until the crumbs look like damp sand.
- Press the mixture firmly and evenly into the base of the lined pan using the back of a spoon.
- Bake the crust for 8 minutes until lightly set, then remove and set aside while you make the batter.
- Whisk 115 g melted butter and 150 g light brown sugar together in a large bowl until combined.
- Add the eggs one at a time, whisking after each addition until the mixture looks smooth and slightly paler.
- Stir in the vanilla extract.
- Add the flour, baking powder, cinnamon, cloves, cardamom, nutmeg, white pepper, and salt. Fold with a rubber spatula until just combined, no dry streaks remaining.
- Pour the batter over the pre-baked crust and spread into an even layer with a spatula.
- Sprinkle 1 tbsp light brown sugar evenly over the top.
- Bake for 22 to 25 minutes until the top is set and a toothpick inserted in the center comes out with a few moist crumbs.
- Cool the bars completely in the pan on a wire rack, at least 30 minutes, before lifting out using the parchment overhang.
- Slice into 12 bars with a sharp knife, wiping the blade between cuts for clean edges.
Notes
Tips for Success
- Press the speculoos crust firmly with the back of a spoon so bars don’t crumble when cut.
- Pre-bake the crust for 8 minutes before adding the batter to keep it crisp underneath.
- Don’t overmix the batter once the flour goes in or the bars turn tough and dense.
- Cool bars completely in the pan before slicing, at least 30 minutes at room temperature.
- Line the pan with parchment paper with an overhang so bars lift out cleanly in one piece.
Variations
- Swirl 2 tbsp cookie butter spread into the batter before baking for a richer speculoos flavor.
- Add 80 g white chocolate chips to the batter for a sweeter, creamier contrast to the spice.
- Press a thin layer of almond paste under the sponge batter for a Belgian frangipane version.
Storage and Reheating
Store cooled bars in an airtight container at room temperature for up to 4 days. They firm up slightly on day two but the crumb stays soft.
For longer storage, wrap individual bars tightly in cling film and freeze for up to 2 months. Thaw at room temperature for about an hour before eating.
To refresh a bar that’s dried out slightly, microwave it for 10 seconds. It won’t crisp the crust again but the sponge comes back to life.
Serving Suggestions
These bars are good on their own with a strong cup of coffee or a pot of black tea. The spice stands up to dark roast coffee particularly well.
For a simple dessert plate, dust the bars with powdered sugar and add a small scoop of vanilla ice cream on the side, the way you might finish a buttery caramel crumb cake. The cold ice cream against the warm spice is worth the extra step.
If you’re putting out a holiday cookie tray, these cut into smaller squares and hold their shape at room temperature for hours, making them easy to plate ahead.
FAQ
Why are my speculoos cake bars sinking in the middle?
A sunken center usually means the batter was underbaked or the oven temperature was too low. Check with a toothpick at 25 minutes, it should come out with just a few moist crumbs, not wet batter. Make sure your oven is fully preheated before the bars go in.
Can I use speculoos cookie butter spread instead of crushed biscuits for the crust?
Cookie butter spread won’t form a firm crust because it doesn’t have the dry structure of ground biscuits. Stick with whole crushed biscuits mixed with melted butter for a base that holds together after baking.
Can I freeze Belgian speculoos cake bars before or after baking?
Freeze them after baking, fully cooled and wrapped individually. Freezing unbaked batter in the pan can make the crust soggy when it thaws. Baked bars freeze well for up to 2 months with no noticeable change in texture.
What’s a good drink to serve alongside speculoos spice bars at a holiday gathering?
Mulled wine or a spiced chai latte mirrors the cinnamon and clove in the bars without competing. Hot black coffee is the classic Belgian pairing if you want to keep it simple.
Are Belgian speculoos cake bars vegetarian?
Yes, these bars contain no meat or fish. They do contain eggs, butter, and flour, so they’re not suitable for vegans or anyone avoiding gluten or dairy.
What’s the difference between speculoos and gingerbread bars?
Speculoos uses white pepper and cardamom alongside cinnamon and clove, giving it a sharper, more complex spice than most gingerbread. Gingerbread leans heavily on ginger and molasses, which speculoos largely skips.
