To prepare blueberry jam filling:

1. Mix jam, cardamom, and vanilla together and set aside

To prepare muffins:

1. Prepare muffin tins by spraying with baking spray or lining with paper muffin liners.
2. Preheat oven to 400 degrees F.
3. Mix dry ingredients in a large mixing bowl, set aside
4. Mix wet ingredients in a medium bowl or large, spouted measuring cup
5. Pour wet ingredients into dry and mix gently until just combined. I use a large fork for this and then scrape around the sides and bottom with a soft, rubber spatula to finish. Remember, lumpy, ugly batter is a good thing here.
6. Fill muffin cups half way with batter.
7. Add one teaspoon of jam to each muffin cup.
8. Fill muffin cups with remaining batter.
9. Top each with one more teaspoon of jam, and using a chopstick or skewer, swirl jam from top to bottom and side to side.
10. You can bake them right away, or let them sit at room temp for 20 minutes before baking to get an even higher rise (pro-tip - I always use this time to scurry around and clean up the mess I've made)
11. Place in preheated oven for 15-18 minutes until puffed, golden, and set. (this is a good time to make your glaze)
12. Remove muffins from oven and let cool slightly before transferring to parchment lined surface where you will glaze them once cooled. (cookie sheet, cutting board, large platter).

To prepare glaze:

1. Place all glaze ingredients in a small bowl and add just enough milk to make a smooth, pourable glaze. Add more confectioner's sugar if it's too thin, or more milk if too thick. You want it thin enough to pour, but thick enough so it doesn't all just run off the muffins.

To glaze muffins:

1. Once muffins are cooled to room temp, spread or pour glaze any way you like. I like to drizzle it over the top, but you could also dip each muffin top.