Make the thyme cream
In a food processor, combine the flour, hazelnuts, cinnamon, cloves, and allspice and process until the nuts are finely ground. Add the butter, egg yolks and lemon zest and pulse until the mixture resembles coarse meal. Add the ice water and pulse just until the dough comes together. Scrape the dough onto a lightly floured work surface and knead briefly. Pat the dough into a disk, wrap in plastic and refrigerate until firm, about 1 hour.