Cream the butter, sugar and eggs: In a stand mixer or in a large bowl with a hand mixer on high, cream the butter and sugar until fluffy and smooth, 3 to 4 minutes. Add the eggs one by one, completely incorporating the first one before adding the second, and making sure to scrape the sides between additions. Beat in the almond extract.
Add the dry ingredients: In a large bowl, stir to combine the flour, baking powder and salt. Lower the mixer speed to medium-low and pour the flour mixture into the butter mixture in four parts, taking time to blend in and scrape the sides of the bowl back to the center between each addition, until all is combined.
Finish the dough and chill: Add the milk 1 tablespoon at a time to the dough and blend until it becomes smooth but firm enough to form balls (you may not need all of the milk). Turn off the mixer and add the cereal, folding it in by hand using a rubber spatula or wooden spoon. Divide the dough in half and roll into logs 2 1/2 inches in diameter. Wrap tightly with plastic wrap and refrigerate until firm, about 2 hours.
Bake and cool the cookies: Position oven racks in the upper and lower thirds of the oven and preheat to 375 degrees F; line two baking sheets with parchment. Remove the cookie dough from the plastic wrap and slice into 1/2-inch-thick discs. Place 6 discs at least 3 inches apart on each prepared baking sheet (refrigerate the remaining dough until ready to bake). Bake until golden and crispy around the edges, 12 to 15 minutes. Let the cookies cool completely on the baking sheets. Once the baking sheets are cool, bake the remaining cookies.