01 - Whisk together the gluten-free flour, sugar, yeast, and salt in a large mixing bowl until thoroughly combined.
02 - Add warm water, vegetable oil, and apple cider vinegar to the dry mixture. Stir until a sticky, cohesive dough forms.
03 - Gently fold blueberries into the dough, taking care not to crush or burst the berries.
04 - Lightly oil hands and shape dough into a ball. Cover bowl with clean towel and place in warm 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.
07 - Roll each portion into a smooth ball. Poke hole through center and gently stretch to form bagel shape. Place on prepared baking sheet.
08 - Bring 2 quarts water to gentle boil in large pot. Stir in honey or maple syrup if using.
09 - Drop 2-3 bagels into boiling water. Cook 30 seconds per side. Remove with slotted spoon and return to baking sheet.
10 - Brush each bagel with beaten egg and sprinkle with coarse sugar if desired.
11 - Bake for 20-22 minutes until deeply golden brown. Cool completely on wire rack before slicing and serving.