Heat oven to 400°F (200°C). Line a baking sheet with parchment and lightly mist or rub with oil so the bottoms crisp without sticking.
In a large bowl, whisk together the flour, baking powder, salt, and xanthan gum until evenly combined.
In a separate bowl, stir the Greek yogurt with the olive oil and honey until smooth. Scrape this mixture into the dry ingredients and fold with a spatula until a shaggy dough forms.
Lightly flour your hands and knead the dough in the bowl for 30–60 seconds just until cohesive (it will feel tacky but should not smear). Let the dough rest 5 minutes to hydrate for easier shaping.
Divide into 6 equal portions. Roll each into a smooth ball, then poke a hole through the center with your thumb and gently stretch to a 2 to 2½-inch ring. Arrange on the prepared sheet with space between them.
Brush the tops lightly with milk and shower generously with Everything Bagel seasoning so it adheres well.
Bake on the center rack for 18–20 minutes until puffed and deep golden at the edges. For extra color, broil for 30–60 seconds at the end, watching closely.
Cool on a rack for at least 10 minutes before slicing to set the crumb.