Preheat the oven to 190°C, convection oven 175°C. Grease a 6-cavity muffin tin well or line with small paper cups.
Sift the flour together with the baking powder and baking soda into a bowl and set aside.
Wash the raisins and soak in hot water for about 20 minutes. Beat the sugar, butter and egg with a mixer until fluffy. Add the flour mixture and vanilla yogurt and mix briskly until smooth.
Remove the raisins from the water and pat dry with kitchen paper. Mix well together with the poppy seed mixture.
Pour half of the batter into the muffin tin. Using two teaspoons, cut 6 dumplings from the poppy seed mixture, place them on the dough and cover with the remaining dough.
Immediately place in the oven and bake for about 25 minutes. When the baking time is over, take them out and let them rest in the pan for 5 to 10 minutes, then remove the muffins from the pan and let them cool well on a cooling rack.
Mix the powdered sugar with the water or lemon juice to make a glaze. Pour it over the muffins and sprinkle with poppy seeds.