Line baking sheets with silicone liners or parchment paper, or spray with cooking spray. Preheat your oven to 375°.
In a large mixing bowl, beat the soft butter, sugar, and brown sugar with an electric mixer at medium speed for 3 minutes.
Dissolve the baking soda in the hot water, and add to the sugar mixture with the eggs, vanilla, and salt. Beat until smooth and creamy, scraping the sides of the bowl with a rubber spatula.
Add the flour and baking powder; stir until barely blended, then stir in the chocolate chips.
Scoop into 1 1/2-2 tablespoon sized portions (mine were 1.3 ounces), then roll into balls. Place the cookie dough balls on a prepared baking sheet 2-3 inches apart.
Bake cookies at 375° for about 9 minutes, or until golden brown on the bottom. The middle should barely be set.
Let the cookies sit on the cookie sheet for 3-5 minutes, then transfer to a wire rack to cool completely.
Melt the chocolate wafers in a microwave-safe bowl in 30-second increments until melted completely. Use a small spoon or knife to spread melted chocolate on the bottom of each cookie.
Place each cookie chocolate side down on parchment paper and press down slightly so the chocolate will spread all the way to the edge of the cookie.
Alternatively, you can dip half of each cooled cookie into the chocolate, then add sprinkles, or other toppings of your choice.