Preheat the oven to 350 degrees. Line a muffin tin with paper liners.
Brown the butter by melting it in a small saucepan over medium-low heat and continue to cook, stirring often, until the butter turns golden brown and has a nice nutty aroma.
Watch it carefully so it doesn't burn. Pour into a dish and set aside to cool to room temperature.
Make the muffin batter by using a mixer to beat the pumpkin puree, sugar, cooled browned butter, eggs, and vanilla extract until creamy and smooth.
In a separate bowl, whisk together the flour, cinnamon, baking soda, salt, ginger, nutmeg, and cloves until well combined.
Gradually add the dry ingredients to the pumpkin mixture until just combined.
Pour the batter equally between the twelve muffin cups.
Make the pecan streusel by combining the flour, brown sugar, and cinnamon together in a bowl.
Cut the butter into the mixture using your fingers until the mixture is course and crumbly.
Add the chopped pecans and mix until well combined.
Sprinkle the streusel evenly over each unbaked muffin cup.
Place the muffin tray into the oven and bake for 17-19 minutes, or until a tester inserted in the center comes out clean.
Remove from the oven and allow to cool for a few minutes before moving them to a rack to cool to room temperature.
Make the brown butter glaze by melting the butter in a small saucepan over medium-low heat and continue to cook, stirring often, until the butter turns golden brown and has a nice nutty aroma.
Watch it careful so it doesn't burn. Pour into a dish and set aside to cool a bit.
Combine the browned butter with the sifted powdered sugar, vanilla extract, and milk until creamy and smooth.
Drizzle the glaze generously over each muffin. Serve and enjoy.
Store the muffins in a sealed container in the refrigerator.