Breakout for TLA-QFN with exposed pad
The key point on this footprint is how to fan-out the inner row of pins.

Some physical dimensions:


0.45 clearance between the inner pads and the thermal pad. 
0.55mm pitch between pads 
0.2mm clearance between pads


Some options:


Using a 0.07mm/0.07mm trackwidth/gap (less than 4mils/4mils) to fanout between outer pads. This is a really high requirement for the PCB manufatcurer and it will increase the the PCB cost a lot.
Using microvias and via-on-pad technology to fanout the inner pad to a different layer. I think this is the only solution. As well, it will be expensive and it will limit your choice of PCB fabricators. 


The number of layers:

I reckon this kind of package is not supposed to use in a 2 layers PCB at all. 2 layers PCB and microvias is not good engineering choice. I think it should be at least 4 layers. You should consider the type of microvias and its aspect ratio.

You might consider to choose a different component with a more "easy-to-use" package.