In a food processor or high-powered blender, combine the red Thai chilies, shallots, ginger, galangal, garlic, lemongrass, candlenuts (or macadamia/cashew), coriander, cumin, tamarind paste, warm water, and oil. Pulse until a smooth paste is formed.
Transfer the pureed paste into a large pot and cook over medium heat for about 30-40 minutes, until fragrant, stirring intermittently.
Once the paste is nutty in aroma and has thickened significantly, add in the sugar, curry powder, paprika, and salt, and cook for another 5 minutes. Again, stirring every so often.
Turn off the heat.
If not using the paste right away, let the laksa paste completely cool and store in an airtight container in the fridge for up to 1 week, or freezer for up to 6 months.