Combine the dry ingredients. Start off by adding the all-purpose flour, baking powder, baking soda, and salt to a bowl, then whisking it all together.
Prepare the blueberries. Reserve about 1 tbsp of the flour mixture and mix it with the blueberries. Then set them aside.
Beat the eggs. Now whisk the eggs on high speed with an electric hand mixer in a separate bowl until they’re pale and fluffy.
Add the sugar, vanilla, and lemon juice. Continue beating the eggs as you add in the granulated sugar. Keep beating for about 3 more minutes, then add the vanilla extract and lemon juice.
Add the heavy cream. Beat the eggs on high speed again and slowly add in the heavy cream.
Sift in the dry ingredients. Begin sifting in your dry ingredients, but not all at once. Add about 1/3 of the dry ingredients at a time, mixing to incorporate them each time.
Add the butter and blueberries. Once you’ve got all your dry ingredients well Incorporated, continue mixing as you add in the melted butter. Then add the berries to the blueberry muffin batter.
Fold the batter and scoop it. Fold the blueberries into the batter using a spatula. Then line the muffin tin with cupcake liners and begin scooping the batter out using a large cookie scoop.
Make the topping. Combine the cold cubed butter, all-purpose flour, salt, cinnamon, and brown sugar in a small bowl. Mix with a fork until all the ingredients are well combined and have a crumbly, dry texture to them.
Bake. Top the blueberry muffins with the streusel topping and bake them in the oven at 350 degrees Fahrenheit for about 35 minutes.