Good French bread is not that easy to find in London… But have you been to Exeter Street Bakery? They serve French and Italian breads as well as yummy pastries to die for, and very honestly, the best Mocha.
The sun hits the little café place inside, which is the nicest thing when having a breakfast in the morning. The two French ladies are very kind and helpful, and they make you want to come back everyday only at the sound of their lovely accent.
Exeter Street Bakery is located in High Street Kensington, in a quite residential area – perfect to come in with your laptop (and yes, there is wifi), there is also one in Finsbury Park.
In brief, if you like a good coffee with a jam cookie, this little bakery/café is a place you would fall in love with.