Mix all the liquid ingredients in a bowl: egg, yogurt and oil.
Cut 2 slices of pineapple into cubes.
Combine the dry ingredients (flour, sugar and yeast) in a second bowl, then add the pineapple and mix.
Pour the liquid ingredients over the dry ones and mix well, until the mixture is uniform.
Divide the dough into cups, up to about 3/4 of the way up, then bake for about 15 minutes in a preheated convection oven at 180 ° C.
The pineapple muffins are ready: let them cool, decorate with pineapple and icing sugar and serve.