Ingredients
Buttery Shortbread Dough
- 1 cup (227g) unsalted butter, softened
- 3/4 cup (150g) granulated white sugar
- 1 large egg
- 1 teaspoon vanilla extract
- 2 1/2 cups (310g) all-purpose flour
- 1/2 teaspoon baking powder
- 1/2 teaspoon salt
The Filling
- 1/2 cup seedless raspberry jam or preserves
- 1 tablespoon cornstarch
Ingredients and Why They Matter
Unsalted butter is the backbone of this recipe; using a full cup gives the dough its classic shortbread richness and that tender, sandy texture that almost melts when you bite into it. Softening the butter first helps it cream properly with the sugar, which traps a bit of air and keeps the cookies from baking up dense. Granulated white sugar sweetens the dough and also affects structure; creaming it with butter creates tiny air pockets that help the cookies hold their shape while still staying delicate.
A single egg adds just enough moisture and binding power to make the dough more pliable and easy to roll into rectangles and logs, while still keeping a shortbread‑style bite rather than turning into a soft sugar cookie. Vanilla extract adds warmth and a dessert‑shop aroma that backs up both the butter and the raspberry filling; even though it’s a small amount, it makes a big difference in flavor. All‑purpose flour gives structure, so the dough can be rolled and sliced without falling apart; the 2 1/2 cups here are calibrated to balance tenderness with stability in the swirl. Baking powder gives a very subtle lift, helping the cookies bake up light rather than overly hard, and the salt sharpens all those buttery and fruity notes so the sweetness doesn’t taste flat.
For the filling, seedless raspberry jam or preserves is the star: it adds color, tartness, and juicy fruit flavor that cuts through the rich shortbread. Whisking the jam with cornstarch before spreading it over the rolled dough thickens it slightly and helps it gel as it bakes, which keeps the swirl pattern neat and minimizes leaking and burning around the edges. Seedless jam is important here so you get clean slices without seeds interrupting the spiral or tearing through the dough when you roll.
Step-by-Step Instructions
I start by making sure the butter is properly softened; it should give easily when pressed but not be greasy or melted. In a large mixing bowl, I beat the softened butter and granulated sugar together on medium speed for about 3 minutes, until the mixture looks light, fluffy, and noticeably paler in color. This step is crucial, because incorporating air into the butter‑sugar mixture helps create that tender, almost crumbly shortbread texture rather than a dense, heavy cookie. Once the mixture is fluffy, I add the egg and vanilla extract and beat again until everything is fully combined and smooth, with no streaks of egg showing.
In a separate bowl, I whisk together the all‑purpose flour, baking powder, and salt to evenly distribute the leavener and salt before they hit the wet ingredients. Then I gradually add the dry mixture to the butter mixture on low speed, mixing just until a soft, cohesive dough forms. At this stage, I’m careful to stop mixing as soon as the flour disappears; overworking the dough can develop gluten, which makes the cookies tough instead of tender. If any dry bits cling to the bottom or sides of the bowl, I gently fold them in by hand with a spatula until the dough is uniform and smooth.
Once the dough comes together, I divide it evenly in half so it’s easier to roll. I place the first portion between two sheets of parchment paper and roll it into a rectangle about 1/4‑inch thick, aiming for fairly squared‑off edges so the swirl looks even later. Keeping the dough sandwiched between parchment prevents sticking and lets me roll without dusting extra flour on top, which could dry out the cookies. I repeat the same process with the second portion of dough, rolling it between fresh parchment into a similar‑sized rectangle. If the dough feels very soft at this point, I slide the parchment‑sandwiched slabs onto a baking sheet and chill them briefly so they’re easier to handle.
To prepare the filling, I whisk the seedless raspberry jam with the cornstarch in a small bowl until the mixture is smooth and the cornstarch is fully dissolved. The goal is to slightly thicken the jam so it doesn’t ooze out as much when you roll or bake the cookies, but it should still be spreadable. Once the dough rectangles are rolled and, if needed, lightly chilled, I peel back the top piece of parchment, then spread a thin, even layer of the raspberry‑cornstarch mixture over each rectangle, leaving a small border along one long edge to allow for jam spread when rolling.
Starting with the long side closest to me, I use the parchment to help gently roll the dough into a tight log, as if I’m rolling a jelly roll or cinnamon roll. I go slowly, lifting the parchment and coaxing the dough over itself, making sure the jam stays inside and the roll stays snug so the swirl will be distinct in each cookie. If any cracks form, I gently pinch them closed as I go. When I reach the end, I press the seam along the log to seal it, then wrap the log tightly in parchment or plastic wrap. I repeat the same process with the second rectangle if I’ve filled both.
Once the logs are wrapped, I place them in the refrigerator to chill until firm—at least 1–2 hours, or even overnight if that’s easier for my schedule. Chilling is non‑negotiable for pretty swirls: the colder, firmer dough slices cleanly, holds the spiral shape, and bakes without spreading too much. When I’m ready to bake, I preheat the oven to 350°F (175°C) and line baking sheets with parchment paper. I unwrap one log at a time, using a sharp knife to slice it into rounds about 1/4‑ to 1/3‑inch thick. If any jam squeezes out at the edges, I just nudge it back onto the cookie surface.
I arrange the slices on the prepared baking sheets, spacing them a couple of inches apart to allow for slight spreading. The cookies go into the preheated oven and bake until the edges are just turning a light golden color and the centers look set, usually around 10–14 minutes depending on thickness and your oven. I watch closely, because shortbread can go from pale to overbaked quickly; pulling them when the bottoms are lightly golden and the tops are still fairly pale keeps the texture tender and delicate. Once baked, I let the cookies cool on the pan for a few minutes to firm up, then transfer them to a wire rack to cool completely.