Make the Blueberry Jam:
Combine frozen blueberries, sugar, and water in a saucepan over medium-high heat. Cook until thickened, stirring frequently (about 8-10 minutes). You’ll know it’s ready when you can pull a spatula through the mixture and see the base of the pan for a few seconds.
Remove from heat and allow to cool completely. Set aside.
Candied Thyme:
Prepare one bowl with pasteurized egg white and another with granulated sugar.
Dip each thyme sprig into the egg white, gently removing excess. Then, dip into the sugar, shaking off any extra.
Let dry on parchment paper for 20-30 minutes until crystallized. This can be made up to 4 hours in advance for garnish.
Make the Cookie Dough:
Preheat oven to 350°F. Line baking trays with parchment paper.
In a bowl, whisk together flour, baking soda, and salt. Set aside.
In a food processor, pulse the sugar and thyme leaves until combined and aromatic.
In a stand mixer, beat the butter on medium speed for 1 minute until light and fluffy. Add the thyme-sugar mixture and continue to beat for 2-3 minutes until pale and creamy.
Add vanilla bean paste, the egg, egg yolk, and the cooled blueberry jam to the butter mixture. Beat for 2-3 minutes until well combined.
Slowly add the flour mixture in batches, mixing on low speed until just combined. Scrape down the sides of the bowl to ensure everything is fully incorporated.
Using a cookie scoop (about 2 tablespoons or 40g per cookie), portion the dough onto the lined baking trays.
Thyme Sugar for Rolling:
In a small bowl, rub the thyme leaves into the sugar using your fingers to release the oils and aroma.
Roll each cookie dough ball in the thyme sugar before placing on the tray.
Bake the Cookies:
Arrange cookie dough balls on the baking tray, leaving about 2 inches of space between each. Bake for 8-9 minutes until the edges are set, but the centers remain slightly underbaked.
While still warm, use a round cookie cutter to “scoot” the cookies into a perfect circular shape.
Allow the cookies to cool completely on the tray.
Presentation:
Once cooled, serve the cookies with the candied thyme for a festive touch. The cookies will remain chewy and soft thanks to the slightly underbaked centers. Enjoy!