Ingredients
Method
Make the lemon curd
- Fill a medium saucepan with 1-2 inches of water. Place a large heatproof bowl on top (you may also use a double boiler for this) Let it come to a boil on medium high heat, then reduce to low and allow it to come to a simmer.
- Add the egg, egg yolks, sugar, lemon zest, lemon juice, and salt to the top bowl. Using a silicon whisk (metal whisks can sometimes leave behind a metallic flavor), mix together. Cook for 10 minutes, whisking constantly. Whisking the whole time helps prevent the eggs from curdling. The mixture will thicken, and will resemble the consistency of Hollandaise sauce. If the mixture is not thickening, turn up the heat, making sure you are still constantly whisking.
- Remove the mixture from the heat and immediately whisk in the 6 pieces of butter. The remaining heat of the curd will melt the butter. Pour the finished curd into a glass jar or bowl. Cover the top of the curd with cling wrap, making sure the cling wrap is touching the surface of the curd. This prevents a skin from forming as the curd cools. Chill for at least 2 hours, it will thicken during this time.
Make the cookies
- In a mortar and pestle, mash up the dried culinary lavender. Doing this is optional, but highly recommended as it releases more lavender flavor.
- In a bowl, whisk together the sugar, lemon zest, and the mashed up lavender. Set aside.
- In a large bowl using a hand or stand mixer fitted with a paddle attachment, beat together the butter, vanilla, and ⅔ cup of the sugar mixture (save the rest for later!) on medium speed. Beat for at least 2 minutes, or until completely smooth and fluffy. Add the flour, and salt. Beat on low speed until the dough begins to form a crumbly ball. It may look as though it will not come together, but just keep mixing and it will. If not, add a Tablespoon of water. Pour the crumbly dough onto a floured work surface.
- Using floured hands, press the dough into a ball and then roll it out to roughly ¼ inch thickness. The shape doesn't matter. Using a 3 inch round cookie cutter, cut out as many cookies as you can, re-rolling the scraps until you are out of dough. I cut smaller holes out of the centers of half of the cookies, linzer style, but this is completely optional. Place the cut out cookies on two baking sheets lined with parchment paper or a silicon baking mat. Place in the freezer and freeze for 10 minutes, or until set up.
- While the cookies chill, preheat the oven to 325°F. Remove the chilled cookies from the freezer and brush the tops with the egg white using a pastry brush. Sprinkle the tops with the remaining sugar mixture. Bake for 12-14 minutes or until the tops are lightly brown. Let the cookies cool on the baking sheet for 10 minutes before transferring to a wire rack to cool completely.
Assemble the cookies
- Once the cookies have cooled and the lemon curd has chilled and thickened in the fridge, assemble the cookies. Spread a thin layer of the lemon curd on the bottom of a cookie. I recommend using a piping bag for this, but a spoon will work as well. Once half of the cookies have the lemon curd, chill them for about 10 minutes. This helps the curd stay on the cookie a little better. Once chilled, spread a layer of blackberry jam on top of the curd layer, it’s ok if they swirl together a little bit. Top with the remaining plain cookies to create a sandwich. Chill the cookies for at least an hour before eating.
- Cookies stay fresh in a sealed container in the fridge for up to five days.