I've wanted to make those for a long sime, so when I found the recipe, I thought it's finally the time to do them ;)
Those are:
Spicy Red Poffins, Sweet Pink Poffins, Sour Yellow Poffins, Bitter Green Poffins and Dry Blue Poffins.

Recipe for 12-14 poffins:
300g of flour
half a glass of sugar
two teaspoons of baking powder
150g of margarine or butter
200ml of milk
2 eggs
a little bit of salt

- mix flour, sugar and baking powder together
- melt margarine/butter
- add eggs and salt to milk and whisk it (this is the part where I added food colorings)
- pour wet stuff into dry stuff and mix with a mixer it until it becomes a dense mass
- add chocolate chips or whatever you want your poffins to have inside
- pour the batter into molds and bake for 15-20 minutes in 200C
- icing is made by mixing powdered sugar with lemon juice (and I used some food colorings as well)

That's the base recipe. For specific colours and flavours I used different fillings and food colorings.
For spicy poffins I used chilli chocolate and red food coloring + decorated with red icing and some Chilli Mango Jelly Belly beans.
For sweet poffins I used M&M's and pink food coloring + decorated with pink icing and some Tutti Frutti Jelly Belly beans.
For sour poffins I used orange marmalade and yellow food coloring + decorated with yellow icing and some Lemon Jelly Belly beans.
For bitter poffins I used dark chocolate with orange peels and green food coloring + decorated with green icing and some Green Tea Jelly Belly beans.
For dry poffins I used blueberry jam and blue food coloring + decorated with blue icing and some Blueberry Jelly Belly beans.

Poffins and Pokemon are © Nintendo