First, prepare the flax egg. Mix 1 T ground flax with 2.5 T hot water and let sit for 10 minutes.
Preheat the oven to 375 degrees and line a baking sheet with parchment paper.
In a large bowl, mix the flour, brown sugar, baking powder, cinnamon, clove, and salt with a spatula until well combined.
With a fork, a pastry cutter, or your hands, cut the cold coconut oil into the dry ingredients until only coarse crumbs remain. The texture should resemble a grainy meal.
To the bowl with the flax egg, add 1/4 cup milk, pumpkin, and vanilla. Stir well, then pour into the dry ingredients and stir gently until combined, but do not overmix. If the dough is too dry, add milk one tablespoon at a time until a cohesive ball is achieved.
Dump dough onto a clean, floured surface and pat into a circle about 1/2 inch thick. Use a sharp knife or pizza cutter to slice into 8 even triangles. Scoop triangles onto prepared baking sheet with about a half inch or so of space in between them to allow room for rising.
Bake 15-18 minutes, or until bottom edges crisp to a light brown. Remove from oven and let cool about 10 minutes, then transfer to a wire rack and cool completely.