Whisk without frothing so the top sets smoothly rather than with a foamy crust.
A buttery shortbread base carries baked lemon custard and a light powdered-sugar snowcap.
As an Amazon Associate I earn from qualifying purchases.
Lemon Snowcap Christmas Shortbread Bars Recipe
Follow the tray sizes, portions and baking intervals in the instructions below.
Total time includes hands-on preparation, required chilling or resting, whole-batch cooking, cooling and finishing.
Kitchen tools you’ll need
- 8-inch square metal pan
- parchment sling
- mixer
- whisk
- zester
- sieve
- cooling rack
- sharp knife
Ingredients
US measures are approximate. Gram weights help keep portions consistent; spice weights vary with density.
Instructions
Mix the base
- Mix the base: Heat oven to 350°F (175°C) conventional or 325°F (165°C) fan. Line an 8-inch square metal pan with a parchment sling. Beat base butter and base powdered sugar just until smooth, then stir in base flour and salt. Press evenly into the pan and prick lightly. Before baking, whisk filling eggs and granulated sugar gently, then filling flour, lemon juice and zest; set aside.
Prebake
- Prebake: Bake the single pan 23–28 minutes until lightly golden. The already mixed filling rests during this bake so bubbles settle; this passive rest adds no separate waiting time.
Bake the filling
- Bake the filling: Lower oven to 325°F (165°C) conventional or 300°F (150°C) fan. Pour filling onto the hot base. Bake 22–27 minutes until edges are set and the center trembles slightly without liquid waves. Whole-batch oven time is 28 + 27 = 55 minutes, including both bakes.
Cool and chill
- Cool and chill: Cool in the pan on a rack 60 minutes, then refrigerate 120 minutes until cold and firm. Cooling includes the pan rest; chill is separate.
Finish
- Finish: Lift the chilled slab, cut a 4 x 4 grid for exactly 16 bars and sift dusting sugar over them just before serving. Timing assumes softened butter at the start; allow extra ingredient warm-up if needed. Scale ingredients without changing oven temperature or layer depth; a larger pan or additional pans change total batch time.
Chef’s Science & Pro Tips
Ingredient science
Pour lemon filling over a hot fully prebaked base to help seal the shortbread against seepage.
Technique & texture
Whisk without frothing so the top sets smoothly rather than with a foamy crust.
Finishing & serving
Dust after chilling and just before serving; custard moisture dissolves sugar during storage.
Storage and make-ahead
| Method | How long | What to do |
|---|---|---|
| Room temperature | 2 hours | Up to 2 hours for serving. Serve filled bars in small batches; return to the refrigerator promptly. Reduce to 1 hour if the room is above 90°F (32°C). |
| Refrigeration | 4 days | Up to 4 days. Keep filled bars airtight at 40°F (4°C) or below. Plain shortbread needs no refrigeration; the assembled filling is why this recipe specifies chilled storage. Separate layers with parchment. |
| Raw freezing | 1 month | Up to 1 month, dough only. Freeze only the shortbread dough, well wrapped; thaw covered overnight in the refrigerator, then shape and complete the recipe's full bake. Make fillings fresh; do not freeze raw egg custard or raw frangipane in assembled bars. |
| Baked freezing | 1 month | Up to 1 month. Freeze fully cooled filled bars airtight between parchment layers. For sandwiches, freezing unfilled baked halves and adding fresh filling gives a crisper crumb. Thaw filled items covered overnight in the refrigerator. |
| Restoring | 2 hours | Overnight refrigerated thaw; 10–20 minutes before serving. Thaw filled items covered in the refrigerator. Let a serving portion stand 10–20 minutes to soften, keeping the total room-temperature exposure within 2 hours. Do not oven-reheat filled items; add fresh powdered sugar or cocoa after thawing where used. |
Notes
- Scale ingredients, including US measures, without changing cookie size or oven temperature. Extra trays increase whole-batch time.
Nutrition
Approximate values per portion from the listed ingredient weights divided into 16 equal portions. Includes required fillings and finishes. Brands, unused coatings and actual portion size affect the estimate.
Frequently Asked Questions
Why bake the base before adding lemon?
The filling is wet; a golden prebaked base holds it better than raw shortbread.
Can bottled lemon juice replace zest?
Juice and zest have different functions; keep 120 g juice and 4 g finely grated fresh zest as listed.
Why is the bake field 55 minutes?
It includes both the base bake, up to 28 minutes, and filled-pan bake, up to 27 minutes.
