In a medium sized bowl add flour and brown sugar, but cold butter into dry ingredients with a fork or a pastry cutter. You can also do this step in a food processor. Pulse until ingredients are just combined. Set aside.
Combine flour, baking powder, lemon zest and salt in a bowl. Set aside.
Measure out milk. Set aside.
Blend shortening, sugar and eggs together in large bowl with hand mixer or with a stand mixer. Beat well 3-5 minutes. Add vanilla.
Alternate adding dry ingredients and milk to the shortening sugar until everything is combined.
Fold blueberries into the muffin batter.
Put muffins papers in muffin tin, using an ice cream scoop or large cookie dough scoop fill each muffin cup 3/4 of the way.
Add a tablespoon of crumble topping to each muffin
Bake in preheated oven for 20 minutes until just slightly browned and tooth pick comes out clean