Mix bread flour, spelt flour, brown sugar, sesame seeds, quinoa, sunflower seeds, millet, oats, and flax seeds together in a bowl.

Combine milk and oil in the bread pan of a bread machine; add flour mixture. Make a well in the center of the flour mixture; pour in yeast. Knead dough according to manufacturer's instructions.

Turn out dough on a floured work surface. Punch down and separate into 16 pieces. Flatten into 5-inch diameter flatbreads.

Place flatbreads on 2 baking sheets; cover with plastic wrap. Let sit in a warm place until risen, about 1 hour. Remove plastic wrap.

Preheat oven to 350 degrees F (175 degrees C).

Bake in the preheated oven until golden brown, about 15 minutes. Cool slightly; slice in half.