Spread groats on a baking sheet in an even layer. Bake at 375° for 10 minutes. Remove from heat; cool completely.
Dissolve yeast in warm water in a large bowl; let stand 5 minutes. Stir in honey and 1/4 teaspoon salt.
Lightly spoon flour into dry measuring cups; level with a knife. Add 3 cups flour to yeast mixture; stir well. Stir in groats. Cover and let stand at room temperature 1 hour to form a sponge (mixture will rise and bubble slightly).
Stir in remaining 1 3/4 teaspoons salt and 1/2 cup sunflower seeds to sponge. Add 2 1/2 cups flour; stir until a soft dough forms. Turn dough out onto a floured surface. Knead until elastic (about 10 minutes); add enough of remaining flour, 1 tablespoon at a time, to prevent dough from sticking to hands.
Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°) 1 hour or until doubled in size. (Press two fingers into dough. If indentation remains, dough has risen enough.) Punch down; cover and let rest 5 minutes.
Divide dough into 2 equal portions. Roll each portion into a 14 x 7-inch rectangle on a lightly floured surface. Roll up each rectangle tightly, starting with a short edge, pressing firmly to eliminate air pockets; pinch seams and ends to seal. Place each roll, seam side down, in an 8 1/2 x 4 1/2-inch loaf pan coated with cooking spray. Lightly coat surface of dough with cooking spray. Cover and let rise in a warm place (85°), free from drafts, 30 minutes or until doubled in size.
Preheat oven to 400°.
Combine 1 teaspoon water and egg white, stirring with a whisk. Uncover loaves, and gently brush with egg white mixture. Sprinkle with 2 tablespoons sunflower seeds. Bake at 400° for 40 minutes or until loaves are browned on bottom and sound hollow when tapped. Cool on wire rack.