The use of alcohol in confections is regulated by the TABC. It is not a part of the cottage food law.
The statute regarding the use of alcohol in confections is Texas Health & Safety Code, Section 431.081.
An inquiry to the TABC in 2014 yielded the following response:
"In order to legally produce food products that are made with alcoholic beverages for commercial purposes, an industrial permit must be obtained. The permit allows the holder to purchase alcoholic beverages for cooking and other non-beverage purposes. The permit fee is approximately $381 every two years. Further information about the permit, including the application and the Licensing Department’s contact information can be found here:
TABC— Director of Excise Tax and Marketing Practices