Here's how to make Samantha Seneviratne's Microwave Chocolate Pudding Cake:FOR THE CAKE6 tablespoons/86 grams unsalted butter, cut into pieces cup/60 milliliters whole milk2 teaspoons pure vanilla extract teaspoon instant coffee or espresso (optional) cup/165 grams packed dark brown sugar1 cup/128 grams all-purpose flour cup/32 grams unsweetened natural cocoa powder1 teaspoon kosher salt (such as Diamond Crystal) teaspoon baking powder teaspoon baking sodaFOR THE TOPPING cup/110 grams dark brown sugar cup/24 grams unsweetened natural cocoa powder teaspoon kosher salt (such as Diamond Crystal) cup boiling waterIce cream, to servePrepare the cake: Add the butter to a 1- to 2-quart microwave-safe souffl dish or casserole, then melt the butter in short bursts in the microwave.Whisk in the milk, vanilla and instant coffee, if using. Whisk in the brown sugar, then add the flour, cocoa, salt, baking powder and baking soda and whisk until just combined.Make the topping: In a small bowl, whisk together the brown sugar, cocoa powder and salt. Sprinkle over the cake batter.Pour the boiling water over the top.Cook in the microwave at full power until you can see the set cake start to emerge through the sauce in various spots and the sauce has thickened, 5 to 7 minutes. (Its OK to periodically stop and check doneness partway through cooking.) The cake will continue to set as it cools.Serve warm, with ice cream.