Butter four 6-ounce heatproof ramekins. Set a trivet in a wide lidded pot.

In a medium bowl, whisk together ¾ cup of almond flour, ¼ cup of unsweetened cocoa powder, ¼ cup of erythritol, 1 teaspoon of baking powder, and a pinch of salt.

In another bowl, whisk together 2 eggs, ¼ cup of Greek yogurt, 2 tablespoons of melted butter, 1 teaspoon of vanilla extract, and the zest of 1 large orange.

Chop 2 oz of sugar-free dark chocolate into small chunks and fold into the wet ingredients.

Gently fold the wet ingredients into the dry ingredients until just combined.

Divide batter evenly among four prepared ramekins, leaving at least 1/2 inch headspace.

Cover each ramekin tightly with foil.

Set covered ramekins on the trivet; carefully pour boiling water into the pot halfway up their sides.

Cover and simmer gently 25-30 minutes, maintaining the water level, until centers reach 160°F and a tester shows no raw batter; melted chocolate may mark it.

Carefully remove the ramekins from the water bath and let cool for 5 minutes.

Run a knife around the edges and invert onto serving plates, or serve directly in the ramekins.

Serve warm.