Room temperature butter means 65-68°F — not just soft to the touch

Creaming butter and sugar properly requires butter at exactly 65-68°F. Too cold and it will not incorporate air. Too warm (above 70°F) and the fat melts, creating a greasy, flat result. The finger test: you should be able to press your thumb in and leave an impression without the butter squishing through. Cut it into cubes 30-45 minutes before use. Microwaving creates hot spots that partially melt the fat.