Opskriften er enkel, så jeg kan lave maden hurtigt.

Because Danish usually adds the definite article to the end of the noun.

• en opskrift = a recipe
• opskriften = the recipe

So -en here is the definite ending for a common-gender noun.

Because opskriften is a singular common-gender noun, and the adjective agrees with that.

In predicative use after er, Danish adjectives usually work like this:

• common gender singular: enkel
• neuter singular: enkelt
• plural: enkle

So:

• Opskriften er enkel = correct
• Problemet er enkelt = correct, because problem is neuter

Also, even though opskriften is definite, predicative adjectives do not take the definite -e form here.

Not exactly.

• enkel means simple in structure or design
• nem means easy

For a recipe, both can work, but the nuance is slightly different:

• Opskriften er enkel = the recipe is simple / uncomplicated
• Opskriften er nem = the recipe is easy

In many contexts, a simple recipe is also easy, so the meanings overlap.

Here så means so or therefore.

It connects the two ideas:

• Opskriften er enkel = the recipe is simple
• så jeg kan lave maden hurtigt = so I can make the food quickly

So it shows a result or consequence.

Because the neutral order in the second clause is subject + finite verb:

• jeg kan lave

Danish main clauses normally put the finite verb in second position. In jeg kan lave maden hurtigt:

• jeg = first element
• kan = second element

So så jeg kan lave ... is completely normal.

You may also see så kan jeg ... in other contexts, but here så jeg kan ... is the most straightforward continuation.

Because kan adds the meaning of can / am able to.

• jeg kan lave maden hurtigt = I can make the food quickly
• jeg laver maden hurtigt = I make / am making the food quickly

So kan expresses ability or possibility, not just the action itself.

Because Danish modal verbs do not use at before the infinitive.

So you say:

• jeg kan lave
• jeg vil spise
• jeg skal gå

not:

• jeg kan at lave

This is similar to English, where we say can make, not can to make.

Yes. Lave is a very common Danish verb meaning make or do, and with food it often means prepare or cook.

So:

• lave mad = cook / make food
• lave maden = prepare the meal / make the food

It is a very natural everyday verb here.

Because maden means the food / the meal, while mad means food in a more general sense.

Compare:

• lave mad = cook, make food in general
• lave maden = make the food, prepare the specific meal

In this sentence, the speaker is talking about a specific meal or dish, so maden makes sense.

Because hurtigt is functioning as an adverb here, modifying the verb lave.

It tells us how the food is made:

• lave maden hurtigt = make the food quickly

In Danish, adverbs are often identical to the neuter adjective form:

• en hurtig opskrift = a quick recipe
• maden bliver lavet hurtigt = the food gets made quickly

So the -t form is very common when describing the manner of an action.

Yes. Danish allows some flexibility, with slight changes in emphasis.

For example:

• jeg kan lave maden hurtigt
• jeg kan hurtigt lave maden

Both are possible.

Very roughly:

• lave maden hurtigt focuses on the action being quick
• hurtigt lave maden can put a bit more emphasis on quickly

The original version is very natural and neutral.

Because the sentence contains two clauses, each with its own finite verb:

• Opskriften er enkel
• jeg kan lave maden hurtigt

In standard written Danish, it is normal to place a comma between such clauses, including before så when it links them.