For the pistachio butter:

1. Preheat the oven to 392 degrees Fahrenheit and place the shelled pistachios on a baking tray lined with baking paper.

2. Roast the pistachios in the oven for 5 minutes and then leave to cool briefly.

3. Place the roasted pistachios in a high-performance blender and blend until creamy.

Tip: The blending process can take a while, as the oils from the pistachios first have to be released to create a cream. If you don't have a blender, you can also use ready-made pistachio butter. 

For the pistachio protein cups:

1. Finely chop the chocolate and then melt together with the coconut oil in a bain-marie.

2. Line 8 muffin cases (made of paper or silicone) with about half of the melted chocolate and allow to set completely.

3. Mix the pistachio butter with the agave syrup and protein powder to create a firm cream. Divide the cream into 8 equal parts and press one part each evenly into the chocolate-lined molds. Repeat the process with each part and then spread the remaining chocolate evenly into the molds.

4. Sprinkle the pistachios over the cups, whole or chopped as desired, and leave to set in the fridge.