PREHEAT OVEN TO 350°.

LIGHTLY SPOON FLOUR INTO DRY MEASURING CUPS; LEVEL WITH A KNIFE. COMBINE FLOUR, BAKING POWDER, AND 1/4 TEASPOON SALT; STIR WITH A WHISK.

COMBINE SUGARS, BUTTER, AND SHORTENING IN A LARGE BOWL; BEAT WITH A MIXER AT MEDIUM SPEED UNTIL LIGHT AND FLUFFY, ABOUT 3 MINUTES. COMBINE 1/4 CUP WATER, EGG SUBSTITUTE, KAHLÚA, AND VANILLA IN A SMALL BOWL. ADD KAHLÚA MIXTURE TO SUGAR MIXTURE; BEAT 2 MINUTES OR UNTIL WELL BLENDED.

GRADUALLY ADD FLOUR MIXTURE; BEAT AT LOW SPEED JUST UNTIL COMBINED. FOLD IN CHOCOLATE CHIPS, WHITE CHOCOLATE CHIPS, AND PECANS. DROP BY LEVEL TABLESPOONFULS 2 INCHES APART ONTO UNGREASED BAKING SHEETS.

BAKE, 1 SHEET AT A TIME, AT 350° FOR 14 MINUTES OR JUST UNTIL SET AND BEGINNING TO BROWN AROUND EDGES AND ON BOTTOMS. REMOVE FROM OVEN; COOL ON PAN 1 MINUTE. REMOVE FROM PAN; COOL COMPLETELY ON WIRE RACKS.