For earth “To spread out“is not like “To create” as spreading out is part of creation
And for sky also “To raise “ is also not like “ To create”” as Raising of height is also part of creation
That means creation had started for heaven before raising height of it and for earth before spreading out of it
But after creation of single heaven he made them in to seven heavens
morever He turned to the heaven, and made them(fasawwahunna) into seven heavens. — Sura 2:29
So He completed(Faqadahunna) them as seven firmaments in two Days Sura 41:12

It is clear that creation of seven heaven was done in two steps
1. creation of single heaven which was in the form of smoke(vapor or foam)
2. then from single heaven seven heavens were made
Which were completed in two days
Simultaneously creation of earth was also completed in two days
Say: Is it that ye deny Him Who created the earth in two Days? 41:9
Both creation of seven heavens and earth was completed in two days
After that he had created all that is on the earth
He set on the (earth), mountains standing firm, high above it, and bestowed blessings on the earth, and measure therein all things to give them nourishment in due proportion, in four Days, in accordance with (the needs of) those who seek (Sustenance).41:10
In Arabic we have to carefully examine these threewords
KHALAQA (TO CREATE)
SAWWA(TO MAKE)
Qada (to complete)
Allathee khalaqa fasawwa 87:2
So it can be concluded that first heavens and earth were created in Two days and after that what is on the earth is created in four days
Quran also mention that single heaven was created before spreading of earth
But Quran describes that seven heavens were completed in two days and earth was also created in two days. so there is not the question of which was created first.
Seven heavens or earth ?
If you ask which was created first heaven or earth ?
Then answer is heaven as per verse 79:27-30
Be carefull about heaven and seven hevens