Process dates in a food processor until finely chopped and they start to form a ball. Add the almonds and cashews and process until finely chopped and thoroughly combined with the dates. Pour in the peanut butter and maple syrup (if using), then process until completely combined and a dough has formed that will hold its shape. If the dough seems too dry or crumbly, add in a little more peanut butter. Stir through the 70g of chopped chocolate.
Grease two donut baking pans/molds with a little bit of coconut oil (or butter) and press dough about halfway up the donut molds. Press firmly! Place the pans in the freezer for about 15 minutes to firm up.
Note, you're going to have leftovers; you can roll the remaining dough into "donut holes" and dip in chocolate later!
Meanwhile, start making the peanut butter cups. Melt the 150g chopped dark chocolate in a heatproof bowl set over a pan of simmering water (don't let any water get in the chocolate!), stirring occasionally. Line a mini cupcake baking pan with 9-10 mini cupcake liners. When chocolate is melted, place 1 teaspoon of the chocolate in the liners and, using a small spoon, smear the chocolate up the sides of the liners (not quite all the way to the top, though). Freeze for 15 minutes until set. Set the remaining chocolate aside.
Make the peanut butter filling by stirring together the peanut butter and icing sugar until combined. Place a slightly-rounded teaspoon of the peanut butter filling into the chocolate cups and smooth the top down.
Lastly, pour another 1 teaspoon of the melted chocolate on top of the peanut butter filling and spread it out to completely cover the tops. Freeze until set, about 20 minutes.
Meanwhile, gently invert the donut pans to remove the dough. If the donuts are having trouble coming out, you can either dip the bottom of the pans into warm water to warm up the coconut oil/butter, which should help the dough slide out... or try to give the dough a little twist with your fingertips to loosen the dough from the pan, which worked for me.
Here, you can either choose to leave the donuts as they are, and just shape the flat sides to be more round (you'll have 12 smallish donuts), or you can mold the donut halves together as I did (you'll 6 huge donuts). To do this, place two donuts, flat sides together, and gently squash together (but not too hard!). Pinch the seams together along the outside, and inside of the donut hole, then smooth over the pinched seams with your fingers. Freeze the shaped donuts again to firm up, about 20-30 minutes - you'll need them to be very firm to dip into the chocolate without falling apart.
Meanwhile, unwrap the peanut butter cups and carefully slice them with a sharp knife into 4 pieces (do this when they're straight from the freezer, otherwise they'll just squash when you try to cut them at room temp). Set aside.
Melt the 200g chopped chocolate (you can use the same bowl that you used for the peanut butter cups). Taking the donuts from the freezer one at a time (so that they'll stay very cold and firm), dip the tops in the melted chocolate and set aside for the chocolate to set.
If you'd like to drizzle over some chocolate, as I did, spoon some of the remaining melted chocolate into a ziploc bag, or similar, snip off a small bit of the corner and once the chocolate on the donuts has set, drizzle over the chocolate from the bag.
To attach the peanut butter cup slices to the tops of the donuts, place a dab of melted chocolate on one side of the peanut butter cup and place that side on top of the donut; the melted chocolate will set and be like a glue to hold the peanut butter cup slice on top.
Store in the refrigerator for about a week; will probably keep in the freezer for longer!