Prepare a 9x12 inch baking tin or roasting tin with non-stick baking paper - allow enough overhang to help lift out the rice crispy slab later.

Place your marshmallows and butter into a large saucepan and allow to melt on a low heat. Keep stirring so it doesn't stick to the bottom of your pan.

Once smooth and very sticky, remove from the heat and add your rice crispies to the pan. Mix them so all the crispies are coated. If your saucepan is too small to cope with this, transfer into a large bowl and mix.

Next, spoon your mixture into your tin. Press it down as tightly as you can - it's very sticky but I find it becomes less and less sticky the more you push it in. I often use a potato masher to finish pressing it in and making sure it's level.

Place in the fridge to chill for 30 minutes - 1 hour (leaving it in there longer isn't a problem either!)

Lift your rice crispy slab out of the tin using the baking paper overhang and transfer to a flat work surface. Use a heart shaped cookie cutter to firmly push through the slab as many times as you can, creating lots of heart shapes. I got 4 larger hearts, 4 medium and a few small ones too, using different sized heart cutters. Don't get rid of the off cuts as obviously, they are just delicious rice crispy treats to enjoy!

In a medium-sized heatproof bowl, melt your white chocolate in the microwave (in short bursts, stirring in between) or in a bowl over a saucepan of boiling water on the hob (don't allow the water to touch the bowl). Once melted, mix in some pink food colouring until you achieve a pale pink colour.

Dip each heart half in the pink white chocolate and then place onto a cooling rack set over a sheet of baking paper. Whilst the (pink) white chocolate is still wet, scatter over your sprinkles. Allow to set at room temperature or in the fridge, then enjoy. Happy Valentine's day!