Сырники вкуснее со сметаной, но сегодня мы ели их с вареньем.

Syrniki are tastier with sour cream, but today we ate them with jam.

Breakdown of Сырники вкуснее со сметаной, но сегодня мы ели их с вареньем.

• есть: to eat
• с: with
• мы: we
• сегодня: today

Questions & Answers about Сырники вкуснее со сметаной, но сегодня мы ели их с вареньем.

Is сырники singular or plural here? What would the singular be?

Сырники is plural nominative here. The singular form is сырник.

So the sentence is talking about multiple pancakes/cakes, not just one. That is why the later pronoun is их = them.

Where is the word are in Сырники вкуснее со сметаной?

Russian usually omits the present-tense form of to be.

So:

• Сырники вкуснее со сметаной
  literally: Syrniki tastier with sour cream
• natural English: Syrniki are tastier with sour cream

There is no separate word for are in this kind of present-tense sentence.

Why is вкуснее used here?

Вкуснее is the comparative form of вкусный = tasty.

So:

• вкусный = tasty
• вкуснее = tastier

The sentence is making a comparison: syrup pancakes are tastier with sour cream.

Why not более вкусные instead of вкуснее?