In a large bowl or the bowl of a stand mixer, combine flour, yeast, milk powder, egg replacer and salt. Whisk well. Add spinach puree, vegetable oil and ¼ cup of water*. Add more water, if needed. Mix and knead to form a smooth, pliable dough. Takes about 6~8 minutes on a stand mixer and 10~12 minutes by hand.
Transfer to a lightly greased bowl, cover and set aside to rise until the dough is almost doubled in volume, about 45 minutes to 1 hour.
Remove the dough onto a lightly floured work surface. Gently deflate the dough and divide it into 8 equal pieces.* Place them on a parchment lined baking sheet, cover and let rise for 30 minutes or until almost doubled in size.
Brush the rolls with milk and sprinkle with the everything bagel topping, if using.
Preheat the oven to 375°F.
Bake for 17~20 minutes or until the tops are golden and feel firm with pressed lightly.
Remove the rolls from the oven and cool them on a wire rack.
Store, well wrapped, for up to 4 days at room temperature, or freeze for up to 1 month.