Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.

In a small bowl, whisk together the gluten-free flour, baking powder, poppyseeds, and kosher salt.

In a large bowl, mix the granulated sugar with lemon zest, rubbing the zest into the sugar.

Combine the dry ingredients with the zesty sugar mixture, folding them together gently.

Cut cold unsalted butter into small cubes and fold it into the mixture until it resembles coarse breadcrumbs.

In a separate bowl, whisk the kefir (or buttermilk), egg, and lemon juice until frothy.

Fold the wet ingredients into the flour mixture until just combined; do not overmix.

Shape the dough into a rectangle about 1 inch thick and fold it over a couple of times.

Form into a 6-inch circle about ¾ to 1 inch thick and chill in the fridge for at least 10 minutes.

Cut the chilled dough into eight wedges and arrange them on the prepared baking sheet.

Brush with additional kefir and sprinkle raw sugar on top before baking for 22-26 minutes.

Let scones cool for 10 minutes, then glaze with a mixture of powdered sugar and lemon juice.