Increasing stages coupling without increasing capacitance in TRX

Hi, In this super simple transceiver, I use the 4.7pF as a means to increase the oscillator frequency during transmit (offset).
However, because this is a very small capacitor the coupling of the oscillator to the BJT amplifier is very small.
Is there any way I can use this configuration but increase the coupling between these two stages?
Maybe a small toroidal transformer to increase the voltage to the RF amplifier (despite the small coupling capacitor)?

I need this small capacitor there, because is is in series with the relatively big capacitance of the RF amplifier stage (where is this capacitance come from?), which in total increases the oscillator frequency during TX.