Error initialising DataFrame with array of shape (1, 1) and extensiondtype
Here's something I noticed while working on  #30277

#### Code Sample, a copy-pastable example if possible

```python
import pandas as pd
import numpy as np
import pytz

temp_1 = pd.Series([pd.Timestamp("2019-07-19 07:04:57")])
temp_2 = pd.Series([pd.Timestamp("2019-07-19 07:04:57+0100", tz=pytz.FixedOffset(60))])
data = np.array([["2019-06-19 07:04:57"]])
pd.DataFrame(data, dtype=temp_1.dtype)  # works
pd.DataFrame(data, dtype=temp_2.dtype)  # fails
```
#### Problem description

The example that fails throws the error:
```
ValueError: If using all scalar values, you must pass an index
```
If I pass an index:
```
pd.DataFrame(data, dtype=temp_2.dtype, index=[0])  # fails
```
then it fails with
```
ValueError: Buffer has wrong number of dimensions (expected 1, got 2)
```
although this doesn't:
```
pd.DataFrame(data, dtype=temp_1.dtype, index=[0])  # works
```
#### Expected Output
I wouldn't expect this behaviour to change based on the `dtype` passed.

#### Output of ``pd.show_versions()``

<details>

/home/SERILOCAL/m.gorelli/pandas/pandas/core/index.py:29: FutureWarning: pandas.core.index is deprecated and will be removed in a future version.  The public classes are available in the top-level namespace.
  FutureWarning,

INSTALLED VERSIONS
------------------
commit           : 3577b5a34d7f9695bc2e99766cc6c49e7bdab6fe
python           : 3.7.3.final.0
python-bits      : 64
OS               : Linux
OS-release       : 4.15.0-72-generic
machine          : x86_64
processor        : x86_64
byteorder        : little
LC_ALL           : None
LANG             : en_GB.UTF-8
LOCALE           : en_GB.UTF-8

pandas           : 0.25.0+1383.g3577b5a34
numpy            : 1.17.3
pytz             : 2019.3
dateutil         : 2.8.0
pip              : 19.3.1
setuptools       : 42.0.2.post20191201
Cython           : 0.29.14
pytest           : 5.3.2
hypothesis       : 4.55.4
sphinx           : 2.3.0
blosc            : None
feather          : None
xlsxwriter       : 1.2.6
lxml.etree       : 4.4.2
html5lib         : 1.0.1
pymysql          : None
psycopg2         : None
jinja2           : 2.10.3
IPython          : 7.9.0
pandas_datareader: None
bs4              : 4.8.1
bottleneck       : 1.3.1
fastparquet      : 0.3.2
gcsfs            : None
lxml.etree       : 4.4.2
matplotlib       : 3.1.2
numexpr          : 2.7.0
odfpy            : None
openpyxl         : 3.0.1
pandas_gbq       : None
pyarrow          : 0.15.1
pytables         : None
pytest           : 5.3.2
s3fs             : 0.4.0
scipy            : 1.4.0
sqlalchemy       : 1.3.11
tables           : 3.6.1
xarray           : 0.14.1
xlrd             : 1.2.0
xlwt             : 1.3.0
xlsxwriter       : 1.2.6

</details>
