Would also like to recommend this course. The lectures are good, the tasks are ok. It assumes familiarity with cryptographic hash functions and signatures, allowing to keep the focus on bitcoin. In some places it delves into some interesting variations of implementations, like Zcash.
I quickly checked the syllabus, however didn't find smart contracts? Do they go into that in some of the videos? How much time do you think this course takes?
No smart contracts - it's a Bitcoin course. Some of the authors also released a tutorial on Solidity and smart contracts, which you can find on Andrew Miller's webpage.
The Coursera class took around 20 hours end to end.