Preheat your oven to 400°F and line a rimmed baking sheet with unbleached parchment paper.

In a large bowl, combine the flour, xanthan gum, baking powder, baking soda, salt, granulated sugar, and lemon zest. Whisk well.

Add the chilled, chopped butter to the dry ingredients, tossing to coat and flatten each chunk of butter with your fingers.

Prepare your blueberries, cutting any large ones in half before tossing them into the mixture.

Make a well in the center and pour in the buttermilk, lemon juice, and honey. Mix gently until the dough comes together.

If the dough is too sticky, press with floured hands until it holds.

Turn out the dough onto plastic wrap and shape it into a 6-inch disk, about 1 inch thick. Wrap loosely and chill in the freezer for about 10 minutes.

Remove from the freezer, unwrap, and sprinkle with about 1 teaspoon of flour.

Cut the dough into 8 triangles using a sharp knife and place the wedges 2 inches apart on the baking sheet.

Brush with cream and sprinkle with sugar if desired.

Bake for about 20 minutes, until puffed and golden.

Allow to cool for 10 minutes before serving.