what is wooden crumb pudding which is a macau dessert?

I think you are talking about "Serradura" (木糠布甸), or sometimes people simply called "Macau Pudding". Below is the receipe:
木糠布甸


圖片參考：http://www.ourrice.com/~Scorpio3210/recipe06-pudding07a_small.jpg

　
材料：Ingredients:
(5吋甩底模) (5"loose leaf cake mould)
馬利餅9塊 marie biscuits 9 pcs
煉奶約70g condensed milk 70g
鮮忌廉300g fresh cream 300g
云呢拿香油數滴 Vanilla Extract few drops
　
做法： (Method:)
1. 將馬利餅壓碎：Press marie biscuits into crumbs.
2. 將鮮忌廉打至七成, 再加入煉奶及云呢拿香油再打至杰身；Whipped fresh cream until soft peak forms, add condensed milk and vanilla extract and beat until firm.
3. 一層忌廉混合物，一層餅碎(用篩把餅碎篩入模中)，一層一層，最後一層必須是餅碎；Pour one layer of the cream mixture follow by one layer of the biscuit crumbs, and so on until finished, the top layer should be biscuit crumbs.
4. 雪凍後即可食用。 Refrigerated then serve.