Butter two baking sheets or line them with parchment paper.
Sift flour, baking soda and salt.
With an electric mixer cream butter with both sugars until light and fluffy. Beat in egg, essence and milk. Add dry ingredients to butter mixture mixing until just combined.
Stir in chocolate chips.
Plop spoonfuls of dough onto baking sheet, well spaced.
Place your baking sheet on the top rack of your oven, set your timer for 6 to 8 minutes for a soft chewy cookie. Bake 10-12 minutes for a crisp crunchy cookie. Carefully watch the first batch and then set the time for subsequent batches. Check after 6 minutes. When you pull your cookies out, the entire top should not be golden brown. Instead, the peaks of the top of the cookie should just be turning brown. At this time, the entire bottom of your cookie is golden brown and the rest of cookie is the same color as the batter. For the crisp cookie, take it out when edges are brown. Remove the baking sheet from the oven and let them stand for a minute or so since the cookies will be incredibly soft and will fall apart if you try to immediately remove them from the baking sheet. After they have firmed up a bit, remove them from the baking sheet to your cooling rack or a piece of wax paper.
Put the other baking sheet with spoonfuls of cookie dough in oven. Cool the first baking sheet to room temperature, clean off the crumbs and then place spoonfuls of dough before placing it in oven.
Yields 25-30 cookies.
Fold the flour in the wet ingredients till the dough comes together. Don't overmix at this stage.
Watch for time carefully for it just takes a few additional minutes to get "burnt" cookies.
For uniform large cookies, use an icecream scoop.
If the brown sugar is lumpy or hard, place a slice of apple or white bread in plastic zipper bag and seal it for a day.