In a small bowl, mix the dry yeast with 1 tablespoon of sugar and half of the warm milk. Let it sit for about 10 minutes until it becomes frothy.

In a large mixing bowl, combine the sifted flour, flax seeds, salt, and baking powder.

In another bowl, whisk together the remaining warm milk, apple cider vinegar, egg, sunflower oil, and the remaining sugar.

Pour the wet ingredients into the dry ingredients and mix until well combined.

Add the frothy yeast mixture and continue to mix until a dough forms.

Knead the dough on a floured surface for about 10 minutes until it becomes smooth and elastic.

Place the dough in a greased bowl, cover it with a damp cloth, and let it rise in a warm place for about 1 hour or until it has doubled in size.

After the dough has risen, punch it down to release the air. Knead it briefly and shape it into a loaf or divide it into smaller portions to make individual rolls.

Place the shaped dough into a greased loaf pan or on a baking sheet lined with parchment paper.

Cover the dough again and let it rise for another 30 minutes.

Preheat your oven to 180 degrees Celsius (350 degrees Fahrenheit).

Before placing the bread in the oven, brush the top with the softened butter.

Bake the bread in the preheated oven for 25-30 minutes, or until the top is golden brown and the bread sounds hollow when tapped.

Remove the bread from the oven and let it cool on a wire rack before slicing.