Cream the butter and sugar together with a wooden spoon.
Add the flour and mix well, bringing the dough together with your hands into a ball.
Transfer the dough to a sheet of folded baking paper (which will go in the slow cooker) and press it down into a circle shape about 2 centimetres deep.
Cut six of the mini Creme eggs in half and press into the dough.
Line your slow cooker pot with another folded sheet of baking paper (to protect the shortbread from burning).
Place the sheet with the dough on top of that sheet. Place either a tea towel or a few sheets of kitchen roll under the slow cooker lid, with the sides folded over the lid.
Cook on high for approx. 2 hours or until the shortbread is lightly golden.
Tip: You must check for burning regularly as all slow cooker cook differently. Don't let it burn, take it out when it starts to become golden. If you have a hotspot in your slow cooker either turn the dish around or move the baking paper around.
Remove from the slow cooker using the edges of the paper.
Leave to cool.
Melt the milk chocolate and drizzle over the top, decorating with the two remaining mini Creme eggs.