Two main styles: the Hong Kong version with smooth yellow custard in a shortbread or puff-pastry shell (a cha chaan teng staple), and the 葡式 (Macau / Lord Stow's) version with caramelized cream filling, brought via Portuguese Macau in 1989.
mistakes
挞 is officially pronounced tà, but very commonly heard as dàntǎ in Cantonese-influenced Mandarin (CC-CEDICT notes 'colloquial pr. dàntǎ'). Either reading will be understood.