Preheat the oven to 350°F. Prepare a baking sheet by lining with a piece of parchment paper and dusting lightly with flour.
In the bowl of a stand mixer, combine flour, sugar, salt, baking soda and baking powder. Add cold butter and mix until the butter is somewhat blended into the flour {there should still be small pieces of butter and the flour should resemble wet sand when squeezed together between your fingers.}
Add in chocolate chunks and then mix in yogurt until the dough just comes together. Do not overmix. There may be a little bit of dry mixture left at the bottom of the bowl; it will get incorporated when you knead the bread.
Turn the dough out onto a lightly floured surface. With floured hands {the dough will be slighly sticky}, lightly knead the dough to ensure all the flour is incoroprated and divide it into two equal pieces.
Shape the dough into two round loaves and place on prepared baking sheet. Lightly dust the top of the breads with flour, then cut a deep cross in the top of both loaves.
Bake for 45-50 minutes until the tops are browned and the loaves are baked through. {You can insert a skewer in the middle to check and make sure the dough is not wet and sticky.
Let cool for at least 20 minutes before slicing.