- Pre-heat oven to 375F and line the muffin tin with 12 paper liner or spray with oil. 
- For Stresuel topping  
- First make streusel with softned butter, flour,  lemon zest and sugar and set aside. 
- For muffins 
- In a medium bowl, mix, flour, salt, baking powder baking soda , poppy seeds  and sugar and set aside. 
- Large bowl, add melted butter, egg, lemon juice, lemon zest  milk and sourdough starter and mix well. 
- To this add dry ingredients and mix well. 
- Transfer to muffin tin lined with papper liner 
- Then divide and add streusel  top of muffin dough. 
- Bake at 375°F for 17- 18 minutes or until toothpick comes out clean. 
- Cool completely in a cooling and rack. 
- If you want you can brush with lemon juice on the warm  muffins. 
- Enjoy with cup of coffee for your breakfast or as snack.