Rave...i think u have overfilled the cupcakes?
Sunsweet...oreo biscuit can eat lah...i got a small pack also wanting to bake orea cupcake also
back to ur qn hope i dun misguide u
diff texture sugar does not affect the texture cos if is fine type easier to 'melt' if using too coarse will take longer time to cream into the butter, only if u subsitute using brown sugar or molasses will alter the taste and colour of ur fruits...
For muffin recipe, usually the wet ingredient (eggs, milk, sugar, vanilla) is mix first, follow then add in the dry sifted ingredient. Do not dump all the dry ingredient at one time. Instead fold in by batches. Do not mix too long for each adding. The texture is usually a bit lumpy and thick, is ok...
For cupcakes recipe, cream the butter n sugar using a electric whisk till light and fluffy, the colour will turn a bit pale white, then add in the beaten eggs gradually and beat at the same time. Make sure the eggs are in room temp or else will curdle which i encounter this scenario b4! Follow then beat in vanilla essence if using. Fold in sifted flour and milk alternative in batches also. I usually mix in 3 batches (flour milk, flour milk , flour milk) I notice i usually dun get lumpy texture compare to muffin recipe during this stage....hehehe pardon me for my nagginess