Make the lemon streusel:

Combine streusel ingredients in a small bowl and pinch together with your fingers until the butter is evenly dispersed and you can form little clumpd. Set aside.

Make the lemon glaze:

combine glaze ingredients in a small bowl and mix to combine. If the glaze is too thin, add more powdered sugar. Too thin, add a bit more lemon.

Make the Lemon Poppy Seed Muffins

1. Preheat oven to 400 degrees F.
2. Line a muffin tin with 12 muffin liners or spray generously with non-stick baking spray.
3. In a large mixing bowl, mix dry ingredients and set aside.
4. In another bowl or a glass measuring cup, mix wet ingredients. whisk them very well with a fork to combine.
5. Add wet ingredients to dry, and stir gently until just combined. Do not over mix and do not whisk. 
6. Divide batter evenly between the 12 muffin liners. I use my largest cookie scoop and it makes 12 muffins exactly. You can fill these right to the top. 
7. divide streusel evenly over the muffins and press down just slightly so it adheres to the muffin batter.
8. bake in preheated oven for 15-18 minutes until puffed and golden brown. After 15 just give a muffin a press with your finger and if it springs right back it is done. If it still seems damp, give it 3 more minutes.
9. Carefully remove from muffin tin and allow to cool on a wire rack.
10. Once cool, drizzle with glaze.