A good first step can be to upgrade your rotors and pads. This offers more consistent braking, significantly more resistance to brake fade and be more resilient under hard conditions, throughout a wider heat range.
Brake fluid is often overlooked but is critical to braking performance. A good quality brake fluid has a higher resistance to brake fade as well due to a higher boiling point and a bigger resistance to absorb moisture.
Once you’ve reached the limits of the factory brake calipers for your application, the only solution is a big brake kit. This can either be a factory caliper from a different car mounted with an adapter or be an aftermarket kit.
The caliper design, amount and size of pistons, rotor size and surface area of the brake pads and not to forget – tires, will determine the amount of brake force you have at your disposal and resistance to brake fade under hard braking from high speeds and track conditions.