1. Cream butter and sugar together using a paddle attachment until white and fluffy.
2. Slowly incorporate the eggs, one at a time until fully combined.
3. Stir in half of the flour and baking powder and soda.
4. Add all of the sour cream.
5. Add the remainder of the flour as well as the poppy seeds. Stir until well combined.
6. In a cupcake tin fill until almost to the top, about 85% of the way. Bake in tins for 20-28 minutes at 180°C until fully done. Remove immediately from the baking tray.
7. While cupcakes are baking, make soaking syrup.
8. To make the syrup, add all ingredients to a small saucepan and bring to a boil over medium high heat. When it reaches a boil, turn down to low, and let reduce until slightly syrupy. Set aside.
9. Let cupcakes cool for 1 minute, then brush with soaking syrup.
10. For the frosting, whisk all ingredients together until just combined. Frost the cupcakes when cupcakes are completely cool.