combine flax with espresso and water then set aside

melt together chocolate chips and butter in 30 second intervals. add brown sugar, vanilla and flax egg to the melted chocolate butter and whisk together.

whisk together ingredients in block 4, ensuring there are no lumps. use a sifter if it looks like you have cocoa balls or baking powder balls. add the flour mixture to the melted chocolate mixture and stir just until combined. fold in the chocolate chips

Use a 1/3 cup measure to scoop dough into muffin papers. Flatten and smooth the tops. Bake in a 350 oven 17 minutes. They'll cave in after they're removed from the oven. While they're warm, push the overhanging outer edges into the center to fill in the caved center.