Preheat the oven to 180°C/350°F/Gas mark 4
Cream the butter and sugar until light and fluffy. Stir in the salt, baking powder, oats, pecans, milk and lemon essence, blending well.
Drop by teaspoons about 2 inches apart on ungreased baking sheets. Bake for about 8 minutes. Cool 2 to 3 minutes, then remove from baking sheet. If cookies harden before removal from sheet, reheat for a few minutes to soften. The cookies will be very thin and lacy. If desired, roll warm cookies, one by one, to form cornucopia shape, pinching points slightly.
