Pistachio Lava Mug Cake

Lightly grease an 8-ounce microwave-safe ramekin or mug with a little oil or nonstick spray.

Place the shelled pistachios in a small food processor or blender and pulse until they form a fine meal (like a coarse flour).

Add the Greek yogurt, egg, maple syrup, baking powder, pinch of salt, and vanilla (if using) to the processor. Blend until the mixture is smooth and combined; the batter will be thick.

If you want a molten center, spoon about half the batter into the ramekin, add the pistachio butter or chocolate square in the center, then cover with the remaining batter. Otherwise, pour all the batter into the prepared ramekin and smooth the top.

Microwave on high for about 60–90 seconds. Start with 60 seconds, then check — the edges should be set while the center remains slightly soft and gooey. Microwave in additional 10–15 second bursts if needed; microwaves vary.

Let the cake rest in the ramekin for 1 minute to finish gently cooking and to set slightly.

Serve warm straight from the ramekin or inverted onto a plate. Top with crushed pistachios, a drizzle of maple syrup, extra Greek yogurt, or a dusting of powdered sugar as desired.