For the Muffins:

1. Preheat the oven to 375°F and line a 12-cup muffin pan with paper liners (this recipe makes about 18 muffins for me, so I prepare another 6-cup muffin tin as well).
2. In a medium bowl, whisk together the flour, baking powder, salt, and spices.
3. Using a hand or stand mixer, beat the butter and sugars together until pale yellow and fluffy, about 2 minutes (you can also just whisk together by hand).
4. Add the eggs, vanilla extract, and oil and beat until smooth.
5. Alternate adding the flour and the apple cider, starting and ending with flour (so, add half the flour first, then all of the cider, and end with the remaining half of flour), gently stirring and folding the batter after each addition. Try not to overmix! This will yield dense muffins.
6. To the empty flour bowl, add the diced apples and 1 tablespoon flour. Gently toss to evenly coat the apples in the flour.
7. Using a spatula, gently fold the apples into the batter.
8. Scoop the batter into the prepared muffin pan and then top each muffin with the streusel topping (instructions below).
9. Bake for 20-25 minutes or until the muffins are golden around the edges and set in the middles.
10. Allow to cool on a wire rack before topping with the apple cider glaze. 
11. Keep covered at room temperature in an airtight container for up to one week.

For the Streusel Topping:

1. To the same bowl used for the muffin dry ingredients, whisk together the flour, sugar, cinnamon, and a tiny pinch of salt.
2. Add the melted butter and stir the mixture until it clumps together and is crumbly.
3. Generously top each muffin with the streusel before baking – I do roughly 2-3 tablespoons per muffin.

For the Glaze:

1. Once the muffins are baked and cooled, make the glaze.
2. In a small bowl, whisk together the ingredients until smooth and creamy. If needed, add a splash more cider or another couple tablespoons of sugar to get it to a drizzling consistency.
3. Drizzle over the cooled muffins and allow to set.