Ingredients
Method
Make the rosemary cookies
- In mortar and pestle, mash up the dried rosemary. Doing this is optional, but highly recomended as it releases more rosemary flavor.
- In a bowl, whisk together the sugar, lemon zest, and 3 ½ teaspoons of the mashed up dried rosemary. 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. Add the flour, salt, and remaining dried rosemary. 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. 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 browned. Let the cookies cool on the baking sheet for 10 minutes before transferring to a wire rack to cool completely.
Make the caramelized white chocolate ganache
- Turn the oven to 240°F. Spread the white chocolate on a baking sheet (don't line or grease it with anything) in an even layer. Place the sheet in the oven and cook for 10 minutes. Remove from the oven and stir/re-spread it in an even layer using a rubber spatula.There may be lumps, that's ok! Place in the oven and cook for another 10 minutes. Repeat this cooking and stirring every 10 minutes process for a total of 6-7 times. The chocolate will turn a light brown color, this will take about an hour. Make sure you keep stirring/re-spreading or it will burn. Once finished pour into a bowl and set aside.
- Heat the heavy cream in a small saucepan until simmering. Pour the caramelized white chocolate in and quickly stir to combine. Immediately remove from the heat. It may look as though it is separating, but if you keep stirring it will come together. The same goes for if it is lumpy. Just keep quickly stirring and it should smooth out. Stir in the salt. Allow the ganache to cool and thicken at room temperature. You want it to be a thick, spreadable consistency, similar to peanut butter. This takes about 40 minutes at room temperature.*
- Spread the cooled ganache on the bottom side of one cookie, and sandwich with another. Repeat with the rest of the cookies. The cookies might slide around with the filling on them, so to prevent this transfer the finished cookies to the fridge for just 10 minutes to set up.
- Finished cookies stay fresh at room temperature in an airtight container for up to a week.
Notes
White chocolate: Make sure you are using baking chocolate bars when caramelizing. Chocolate chips won't caramelize smoothly in the same way.
Thickening the ganache: I have learned that you cannot put this ganache in the fridge to thicken. It causes the chocolate to sieze up and become grainy. It's best to let it thicken on the counter.