Cream butter until light and fluffy, slowly blend in sugar and evaporated milk, and beat until smooth.
Scoop up by rounded measuring teaspoonfuls, shape into balls and arrange 1 1/2" apart on ungreased baking sheets.
With little finger, make deep dents in tops of balls and, using an eyedropper, add a few drops bourbon; pinch tops to seal.
Chill 1/2 hour.
Melt chocolate bits in the top of a double boiler over simmering water, add water a little at a time and beat until smooth.
Keeping chocolate warm over hot water so it doesn't harden, spoon over balls, coating evenly.
Top each ball with a pecan.
Chill 2-3 hours before serving.
Store airtight in refrigerator or other cool place.