Big failure

Hi there. Please advise if i should be using the top or the botton element to bake. Preheated the oven for 10 minutes and baked 150 degree for close to an hour. Used the top element for first 10 minutes. Top burnt. Switched off n turned on the bottom element. Thank you

What's the reason for popping bubbles

Seems like it was too hot. I used the top and bottom elements together. Oven size might play a role here. Perhaps you can try to reduce 10 degrees next time? The popping bubbles happen because there is trapped air in the dough. They need to be popped before baking (step 7).

Thanks for the tips. Will try as suggested. Mine is a portable oven, smaller than a built-in. Just recalled I pre-heated for 10 mins. Shouldn't have. 'Ll give it a second try.

Preheating is needed but perhaps at a lower temperature. Since it's a smaller oven, the metal heater is closer to the surface of the cake batter. Keep an eye on the colour. If it darkens too quickly, place a piece of baking paper or aluminium foil over the batter.