How to Make It
In a small bowl, dissolve 1 of the bouillon cubes in the hot water. Let the broth cool completely, then refrigerate until chilled, about 15 minutes.
In a food processor, pulse both flours with the sugar and salt. Scatter the butter on top and pulse until a coarse meal forms. Add the broth and pulse until the dough comes together. Transfer to a work surface and gather into a ball. Cut in half and pat into disks; wrap in plastic and refrigerate for 1 hour.
Preheat the oven to 400°. Line 2 baking sheets with parchment paper. On a lightly floured work surface, roll out each disk of dough to a 12-inch round and transfer to a prepared baking sheet. Brush the rounds with milk and sprinkle with rosemary. Finely grate the second bouillon cube on top.
Bake the crackers for about 18 minutes, until crisp. Let cool completely, then break into large shards and serve.