Preheat oven to 325
Line a 12 cup muffin tin with muffin papers.
Stir together 1 ¼ cups flour, granulated sugar, baking powder and salt in a large bowl. In a separate bowl, whisk together the egg, beer, vanilla and vegetable oil. Stir the wet ingredients into the dry ingredients, batter will be thick.
Add batter to muffin tins, about ½ way full.
Combine the remaining 1 ¼ cups flour, brown sugar, and cinnamon in a bowl. Drizzle with melted butter, stir together until crumbs form.
Add the crumbs onto the top of the muffin batter until cups are slightly mounded.
Bake at 325 for 32-36 minutes or until the top crumbs have just started to turn golden brown. Allow to cool to room temperature, chill until ready to serve. Dust with confectioners sugar prior to serving.