Preheat your oven to 350 degrees Fahrenheit and line a baking sheet or two with parchment paper. Set aside.
Beat the butter for about a minute on medium speed until it's smooth in the bowl of a stand mixer or in a large bowl using a hand mixer.
Add the sugars to the bowl.
Beat for about 2 minutes, until the mixture starts to turn smooth and just a little bit fluffy.
Add the eggs and vanilla and beat on medium speed until they're well combined (about 45 seconds), scraping down the sides of the bowl now and then to ensure everything is incorporated.
Add the flour, salt, and baking soda to a separate bowl and whisk them together to ensure the baking soda and salt are evenly distributed through the flour. Dump the flour mixture into the butter mixture.
Mix on low speed, just until the dry ingredients are incorporated completely.
Add in the chopped Maltesers and stir them in with a wooden spoon or rubber spatula.
Roll the dough into balls about 1.5 tablespoons at a time and place the balls on the cookie sheets, about 12 to a large sheet (8 to a small sheet).
Bake each pan for about 10-11 minutes, or until the edges of the cookies brown ever-so-slightly. It's a good idea to watch them after about 8 minutes of baking.
Let the cookies cool on the pan for several minutes until they firm up enough to transfer to a cooling rack.
Enjoy them with a glass of milk while they're still warm and the chocolate malt balls are still nice and soft.
These cookies freeze well in an airtight container for up to 1 month.