Line two baking sheets with parchment paper and set aside.
Mix the golden flax meal and water in a small bowl until well combined. Let sit for 5-10 minutes to thicken.
Mix together the soy milk, honey, and 2 tablespoons (28 g) of butter in a microwave-safe bowl. Microwave until the mixture reaches 105º F-115º F, about 45 - 60 sec
Add the yeast to the warm milk mixture and stir. Let sit for 8-10 minutes or until frothy.
In a large bowl, whisk together the spelt flour and salt. Set aside.
When the yeast mixture is ready, pour it all at once into the flour mixture. Stir to combine, then stir in the flax “egg” mixture..
If using a stand mixer, knead the dough with a dough hook on medium speed until the dough forms a soft and smooth ball, about 5-8 minutes. If needed, add more flour, 1 tablespoon at a time, until the dough pulls away from the sides of the bowl. If kneading by hand, knead for about 10 minutes on a lightly floured surface.
Lightly spray a clean bowl with cooking spray and place the dough in the bowl. Cover with plastic wrap or a clean kitchen towel. Allow the dough to rise in a relatively warm environment for 1 1/2 -2 hours or until puffy and doubled in size.
Gently deflate the dough and divide it into 8 equal portions (about 100 g each) to make large buns (or 16 portions to make small buns). Shape each piece into a ball.
Place the balls on the prepared pans, leaving at least 3” between each ball.
Flatten each ball slightly with your palm or another flat object, then cover again with plastic wrap and a tea towel and let rise for another 30 minutes or until the dough balls are puffy. When poked gently, the indentation from your finger should spring back slowly when the balls are ready.
Preheat the oven to 350º F (180º C).
When the buns have risen, melt the remaining butter and, using a pastry brush, brush it on the buns. To make seeded buns, sprinkle buns with the seeds of your choice.
Bake the buns one tray at a time for 15-20 minutes, or until the buns are golden.
Remove the buns from the oven and brush with melted butter to give the buns a delicious buttery crust. If you've made seeded buns, apply the melted butter carefully, to avoid brushing the seeds off the buns.
Let buns cool on the pan for 5 minutes before removing to a wire rack and cooling them completely.
When cool, use a serrated knife to split the buns horizontally before serving.