In a medium bowl, sift the flour, salt, and baking powder together. In a large bowl, whisk the eggs, melted butter, sugar, lemon extract, vanilla extract, milk, and lemon juice.
Stir the dry ingredients into the wet ingredients just until combined.
Toss the raspberries in the remaining flour and add to the batter.
Fold the raspberries and pour batter so each muffin cup is 3/4 of the way full. Sprinkle a few more raspberries over the top if desired.
Combine flour, sugar, and cold butter in a separate bowl. Use a pastry cutter or fork to cut the butter until a crumble mixture forms.
Sprinkle the topping over each muffin.
Bake for 18-20 minutes. Remove from the oven and allow the homemade muffins to cool on a wire rack after resting in the pan for a couple of minutes.
Once the muffins have cooled, they are ready to serve or can be stored for later!