Set softened unsalted butter and granulated white sugar in a bowl at 68°F room temperature. Beat for 2 to 3 minutes with firm circular strokes and scrape the sides once at minute 2. The mixture should turn pale and fluffy with tiny sugar trails through it. Stop there because go past 4 minutes and the cupcakes can rise too fast then sink in the middle.

Add the large eggs one at a time while the bowl stays near 68°F, then mix in whole cultured buttermilk, pure vanilla extract, green gel food coloring and distilled white vinegar for 60 to 75 seconds. Fold in all-purpose wheat flour, Dutch-process cocoa powder, fine sea salt and baking soda with a rubber spatula in a J-shaped motion. The batter should look thick and satin-smooth with a deep green color and a few tiny cocoa specks. Don't beat once the flour disappears because extra mixing makes the crumb chewy.

Keep the batter at room temperature and divide it into 12 cupcake liners, filling each about two-thirds full. Use a scoop-and-drag motion so the batter lands in uneven mounds rather than flat puddles. The liners should look full but not crowded, with little peaks and dips on top. Fill higher than three-quarters and the batter spills over the edges instead of doming. (I tried filling them almost to the top once, cute idea until the tray looked like one giant green sheet cake.)

Bake the filled muffin tin in a 350°F preheated oven for 17 to 19 minutes. Rotate the tin once at minute 12 so the back cupcakes don't brown faster than the front. The tops should spring back lightly and the edges should look set with a faint darker green ring. Pull them late and the crumb dries out around the liner.

Beat full-fat block cream cheese and unsalted butter for frosting at 65°F for 90 seconds, then add powdered cane sugar in two additions and mix for 2 more minutes. Press the frosting against the bowl side between turns so no cream cheese lumps hide inside. The frosting should look thick and smooth with soft ridges that hold their shape. Use cream cheese that's too warm and the frosting slumps before it ever reaches the cupcakes.

Cool the cupcakes to 72°F or lower for at least 25 minutes, then spread frosting over the tops with a loose swirl motion. Work for 8 to 10 seconds per cupcake so the frosting sits high but still looks relaxed. The finished cupcake should show a soft green edge beneath the white frosting and a few crumbs clinging to the swirl. Frost too soon and the cream cheese melts into a shiny slide.