Prepare your muffin tin with muffin liners and pre-heat oven to 175C / 347F (no fan).
In a large bowl, cream room temperature butter and sugar with an electric hand mixer for a few minutes until light and fluffy, then whip in the egg one by one slowly, then the vanilla extract.
After, slowly pour in the oil while continuing to whip the mixture, then in the same way, slowly pour in the room temperature milk and keep whipping the batter.
Sift in the dry ingredients (flour, baking powder, salt) then switch to a rubber spatula and fold the dry ingredients in. Do not overmix at this point.
In a small bowl, mix vinegar with baking soda. It will be super bubbly. Immediately fold the vinegar mixture into the muffin batter just until combined.
Take out about 24 pieces of raspberries and carefully fold the rest into the muffin batter, be careful not to mash them while folding.
Pipe or spoon the muffin batter into the cavities of your muffin tin equally until about ¾ of each. Then, press 2 raspberries each on top.
Bake the muffins for about 20-22 minutes or until a toothpick inserted comes out clean. Do not overbake the muffins as they can dry out.
Serve the muffins fresh or store them at room temperature for 2-3 days in an airtight container.
Notes
INGREDIENT NOTES
All ingredients must be at room temperature to properly emulsify: eggs, butter, and milk.
The baking soda and vinegar mixture is my signature baking hack to make muffins and cupcakes super moist and fluffy. Do not skip it.
Fresh raspberries work best for any muffin recipe, but make sure not to mash them while folding. Frozen raspberries can be used too. See notes in the technique.
You might be able to make more or less mini muffins with this recipe, depending on the size of your mini muffin cases
TECHNIQUE NOTES
A digital scale is required for a consistent, happy baking experience.
Do not overwork the muffin batter. After the wet ingredients are whipped up, switch to a rubber spatula to incorporate the dry ingredients.
Always pre-heat your oven and consider using a digital oven thermometer for the best results.
When whipping in the eggs, oil, and milk, make sure they are all at room temperature otherwise the batter will break.
Also, make sure that you whip in the eggs, oil, and milk slowly. Do not pour these wet ingredients in all at once as that can also break the muffin batter and it can curdle.
Baking these muffins takes 22 minutes in my oven however focus on the texture, not the time. Apply the toothpick check (it should come out clean) to avoid muffins underbaked, however, do not overbake them as that would result in a dry texture.
Frozen raspberries can be used too but do not thaw them. If frozen raspberries are used, you might need to increase the baking time by 2-3 minutes due to their extra moisture.