Learn Spanish (Spain): Bate los huevos y añade la sal.

They are affirmative informal commands (telling someone what to do using the tú form). To form a tú command for regular -ir verbs like batir (to whisk) and añadir (to add), you use the present tense él/ella ending, which is -e.

Is it normal to use the informal tú form for recipe instructions in Spain?

Yes, it is very common! In Spain, recipes, blogs, and casual manuals often use tú commands to sound friendly and direct. You will also frequently see the infinitive forms used as general instructions (for example, batir los huevos instead of bate los huevos).

I noticed it says la sal. Aren't words that end in "-l" usually masculine?

Yes, most nouns ending in "-l" are masculine (like el papel or el sol). However, la sal (the salt) is a very common exception that you just have to memorize as feminine. Another cooking-related exception is la miel (the honey).

Does the verb batir only mean "to whisk" or "to beat" in cooking?

It is the standard word for whisking, blending, or beating ingredients in the kitchen. Outside of cooking, you will also hear it used to mean "to beat" a record in sports (batir un récord).