Bake until cake springs back when done (40 to 55 minutes). (betterbaking.com)
Bake until cake springs back when gently pushed with your finger in the middle and a toothpick comes out clean, about 30 - 40 minutes. (holajalapeno.com)
Bake for 13 - 15 minutes (found this was done after 12 minutes) or until top of cake springs back when touched. (eatpicks.com)