Line an 8x8 inch pan with parchment paper leaving extra paper to use as handles later.

In a large heavy bottomed pot, melt butter over medium heat. Add fluff, sugar, evaporated milk, and salt. Attach your candy thermometer to the pot and bring the mixture to the "softball stage" (225ºF to 235ºF) This should take about 6 to 8 minutes.

Immediately turn off the heat and add the dark chocolate chips, vanilla, and chilli powders to the mixture. Stir well to mix it all together.

Pour into the 8 x 8 inch pan and smooth the top with a silicon spatula. Let the fudge cool to room temperature (about 5 minutes) and then put it into the fridge for 2 hours.

Cut fudge into 1 inch square pieces and serve.