01 - Whisk together gluten-free flour, sugar, yeast, and salt in a large mixing bowl until thoroughly combined.
02 - Pour warm water, vegetable oil, and apple cider vinegar into the dry mixture. Stir vigorously until a sticky, uniform dough forms.
03 - Gently fold blueberries into the dough using a spatula, taking care not to crush or burst the berries.
04 - Lightly oil your hands and shape dough into a smooth ball. Cover the bowl with a clean towel and place in a warm, draft-free area for 45 minutes until slightly puffy.
05 - Preheat oven to 425°F and line a baking sheet with parchment paper.
06 - Dust work surface with gluten-free flour. Divide dough into 8 equal portions. Roll each into a smooth ball, press a hole through the center with your thumb, and gently stretch to form the bagel ring. Arrange on prepared baking sheet.
07 - Bring 2 quarts of water to a gentle boil in a large pot. Stir in honey or maple syrup if using.
08 - Carefully lower 2-3 bagels into the boiling water. Cook for 30 seconds per side, then remove with a slotted spoon and return to the baking sheet. Repeat with remaining bagels.
09 - Brush each boiled bagel with beaten egg wash and sprinkle generously with coarse sugar.
10 - Bake for 20-22 minutes until deep golden brown. Transfer to a wire cooling rack and let cool completely before slicing and serving.