Preheat oven to 425 degrees.
Lightly oil a 9″ pie pan or cast iron skillet.
Sift together dry ingredients. Work in softened vegan butter until just combined and the mixture has the texture of coarse crumbs. Using a wooden spoon or your hand, mix in vegan yogurt. Knead just so it all comes together, no more than a minute. Add another handful of flour if dough is sticky. Dough will be thick.
Gently press dough into a round and place in prepared pan or skillet. Resist urge to smooth the top. Baking turns that craggy top into a delectable crust. Besides, Irish soda bread is rustic and not meant to be prettified. Now, be bold, and slash a cross into the top. This ensures even baking.
Bake for 30 minutes, until top is brown and crusty and loaf sounds hollow when tapped. Allow to cool slightly, then slice thin.