In a medium skillet, brown your butter until it's deeply golden, about 10 minutes. Immediately pour the butter into a heat-safe bowl to stop the browning, add a single ice cube and stir until it's completely melted. Let the butter come back to room temperature.

Preheat your oven to 350 degrees and grease an 8-inch square cake pan. Optionally, line the pan with parchment paper with overhanging edges for easy removal. In a large bowl, beat together the room-temp brown butter, oil, 1/2 cup sugar, eggs, sour cream, vanilla extract, almond extract, flour, poppyseeds, baking powder, and salt. This is a bit of an odd mixing method, but trust the process- you want to just beat everything together at once until just combined. The batter will be thick.

Evenly spread the batter into your prepared cake pan, and sprinkle the additional sugar evenly over the top. Bake the cake for 20-25 minutes, or until a cake tester comes out with just a few crumbs clinging to it. Let the cake cool completely before slicing and serving.